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Tech Talk: Using USB-C and DisplayPort over Alt Mode

Continuing our discussion on display technologies, let’s turn our attention to USB-C and DisplayPort. The DisplayPort protocol, which used to have a unique connector, is now transferred by way of the USB-C connector. The Type-C connector delivers DisplayPort technology via an Alternative Mode (Alt Mode).

With USB-C you get:

Even though USB-C is capable of supporting all of these features, not all of them are present all the time. Users will need to know the specifications of their devices to understand the display protocols supported.

What is Alt Mode?

Alt Mode is a term you will come across frequently when investigating USB-C.

Alt Mode is a functional extension of USB-C which enables the USB connection to carry non-USB signals. Alt Mode(s) are optional capabilities that are unique to the USB-C connector or port that allow technologies, like DisplayPort and Thunderbolt 3, to be transmitted. Knowing what devices and ports support the various Alt Modes may be confusing and, at times, frustrating.

DisplayPort over Alt Mode

DisplayPort Alt Mode (DP Alt Mode) allows a USB-C equipped computer to connect directly to a display or monitor. The monitor will need to have a USB-C port for you to make this connection. You can still use a USB-C equipped laptop with monitors that have more traditional video ports, such as VGA, DVI, HDMI, and DisplayPort but you will need to get a USB-C video adapter.

What do I need to know before using DisplayPort over Alt Mode?

  • Confirm your computer’s USB-C port supports DP Alt Mode
  • Read the tech specs on the USB-C video adapter to ensure it supports the resolutions and refresh rates you want
  • If you are interested in a USB-C MST video adapter or laptop docking station, make sure your video card also supports MST

Our next and final display technology post will offer tips for using Thunderbolt 3 and MST.

Catch up on Display Technology 101 and tips and tricks for using MST and DisplayPort.

Stay tuned!


  1. Horst Wischnat 4 years ago

    How to check •whether my computer’s USB-C port supports DP Alt Mode

    • Susan Mutterback 4 years ago

      Hi Horst,
      Thanks for reading this post! The best place to find this information is your laptop’s manual or website.

  2. anilroy 4 years ago

    thanks for information of usb-c it is quite interesting for me to learn the new technology and their generations

    • Al French 11 months ago

      I want to connect my Surface Pro 3 to two 2K monitors. If I buy an MST hub with USB-C input cable, will it work with an usb-c (female) to mini DP adapter?

      • Danielle at 11 months ago

        Hi Al! Unfortunately, if you were to use an adapter it would likely remove the MST functionality of the Surface Pro’s Mini DisplayPort port. Your best option would be MSTMDP123HD or MSTMDP122DP with two DP2HDMI2.

  3. Paulus 4 years ago

    Thanks for this, it is nice to know someone else understands this. Indeed it is frustrating dealing with parts suppliers to confim the adaptors actually work!

    I have a Zenfone 3 deluxe that supposed to support USB-C Alt Mode, but I am having a terrible time getting a port replicator. I ended up just buying a Miracast dongle instead, and casting the phone to the monitor, then using usb-c for charging, keyboard and mouse, but still I want a docking station.

    Hopefully more adaptors and port replicators will come out, and the people selling them will actually know if they work or not!

  4. Mathieu 4 years ago

    I have a portable usb-c screen with DP alt mode compatibility, I connect it for now to mij mini gaming rig that only has USB-C 3.1, will there ever be an adapter that connects from my desktop DP and usb to an USB-C DP alt connection?

    • Barry Weston 4 years ago

      Hello Mathieu,

      It sounds like you are trying to find a solution that would require USB-C with DP-Alt mode on your host device. Unfortunately, that is not technically possible.



    • Gagarin235 3 years ago

      I think i have seen pci-e usb-c adapters with dp-alternate mode passthrough …
      something like this ..
      Depending on HOW small your mini gaming rig is, it could be your solution …

  5. Carson 4 years ago

    I got a Dell U3818DW monitor, it does have a USB-C port which supports DP Alt Mode. And I got a Pixel 2 XL phone.

    But why, the monitor still not able to display anything after connecting them with a USB-C cable.

    • Barry Weston 4 years ago

      Hi Carson,

      Unfortunately, the Pixel 2 XL does not support video out over the USB-C port. At this time, there are no products we could recommend to connect your Pixel 2 XL directly to a display.


      • Carson 4 years ago

        Oh I see…so that means I must use a USB-C to HDMI or Display Port converter in order to transfer display signal to a compatible monitor right?

  6. Christopher 4 years ago

    I know the Asus B9440UA-XS74 supports video out over the USBC3.1 ports, as it comes with an adapter to add a single HDMI output, and has an optional docking station for up to two connections from 2xDP,1xHDMI,1xVGA. Does this imply that I would be able to use your 3 HDMI MST hub for my 3 monitors from this ultrabook, given that the Intel® HD Graphics 620 is supposed to support up to 3 displays? Asus is not particularly helpful with specification (the page on their site loads blank) or customer service inquiries (taking sometimes weeks to get a non-answer). Thank you.

    • Barry Weston 4 years ago

      Hi Christopher,

      The answer to your questions isn’t a simple yes or no.

      The first thing to consider is the maximum number of displays your Intel HD 620 graphics card supports. Intel graphics cards only support a maximum of 3 total displays. This includes the display of your laptop. Therefore, to use 3 external displays you will be required to disable your laptop display via display settings.

      Second, you will need to find out if the Asus (ultrabook and docking station) supports full DisplayPort 1.2. If it does, use of MST accessories, such as our MSTDP123HD will work. WIthout DisplayPort 1.2 support, the MST hub will not function correctly.

      Hopefully, that helps. Let us know if you need anything else.

      You can also speak with one of our Technical Advisors by phone or live chat. They can be reached here: StarTech.Support


  7. Gabriel 3 years ago

    Hi Guys,
    One question. My monitor has an USB-C input, but my notebook doesn’t. I bought an adapter USB-C to VGA to be able to use it, but it didn’t work.
    Do these adapters need to always have the output source as being USB-C?

    • Andrea McDonald 3 years ago

      Hey Gabriel, in order to drive a USB-C display your notebook needs to be USB-C enabled as well. Let us know if you have any further questions.

  8. Mak 3 years ago


    Just to want make sure that if a USB C to DisplayPort ADAPTER works for a laptop, will a USB C to DisplayPort CABLE that supports Altmode also work for the same laptop? My question is, does it need to be a USB C video adapter as mentioned in the article to work or will a cable also work?

    • Elyse Trevail 3 years ago

      Hi Mak, if your laptop supports DP-Alt mode, then any USB-C to DP adapter or cable will work.
      If you are looking for a cable solution rather than an adapter check out this product. If you have any further questions, feel free to contact our Tech Support Team via Live Chat or Phone @ 1 800 265 1844. Thanks!

  9. jay 3 years ago

    Do you make a pci-e card that outputs DP alt mode over USB-C, so that video out over DP can be added to a desktop? This is for a SuperMicro server with old Matrox g200ew graphics that won’t take a second video card and is incompatible with DisplayLink. Thank you

    • startech 3 years ago

      Hey Jay, our USB-C cards won’t help with that, you would need a graphics card. I encourage you to contact our Tech Support Team directly at 1 800 265 1844 or via Live Chat. Thanks!

  10. Kate 3 years ago

    Hi, I would really appreciate your help. I spend many hours trying to find the answear but still have doubts. I’ve got dell 7710 with thunderbolt 3 and need usb c Alt Mode to be able to use cintiq graphic tablet I am hoping to buy. Would you say thunderbolt 3 can work as usb c alt mode?

    • Elyse Trevail 3 years ago

      Hi Kate, thanks for contacting us. By the sounds of it, you have done a lot of research already and we would agree with you that this should work, however, to be 100% sure we recommend you either contact Dell or the tablet maker directly to ensure your tablet will work as desired. Good luck!

  11. John 3 years ago

    USB-C MST is hard to find information about the internet, USB-C MST brings up product descriptions and MST is too generic. I’d recommend either linking to another article about MST or spell out the Acronym so people can research it on their own. With DP over USB-C apt mode, what does the graphical rendering? Is it simply pulling the display output from my graphics card giving me the same performance as if I plugged into the display output natively or is it coming from somewhere else, presumably with significantly less performance?

    • Danielle Mayea 3 years ago

      Hi John,

      MST stands for Multi-Stream Transport. Graphics cards that support MST allow rendering multiple independent displays over a single video port. In those cases, the graphics card itself is rendering the displays. When it comes to USB-C and Thunderbolt 3 however, the displays connected to these ports are rendered by the USB-C/Thunderbolt 3 chipset, in most cases. For performance information on using MST over USB-C or Thunderbolt 3 we recommend contacting the computer manufacturer.

      Thanks for your question!

  12. Drake 3 years ago

    I have an HP Elite lapdock that worked great with my Galaxy S9 via a Thunderbolt 3 USB-C cable, but when I try using my Razer Phone with it, only the keyboard works. No video signal goes out. I have read about users on the internet that were able to use the HP Elite lapdock with their Razer Phones, but it doesn’t work with mine. I even rolled back to Android 7.1.1 which is what the phone shipped with, and it still doesn’t work.

    • Danielle Mayea 3 years ago

      Hi Drake,

      We recommend contacting Razer for troubleshooting the video output feature on your phone.


  13. John 3 years ago

    Does DP-Alt Mode work with usb-c/thunderbolt 3 ports? If not, is there an adapter?

    • Danielle Mayea 3 years ago

      Hi John,

      Thanks for checking out this article! Whether a USB-C port supports DP-Alt mode depends on the USB-C device manufacturer. We suggest contacting the manufacturer of your device to find out if your computer supports video over USB-C. Thunderbolt 3 will, by default, support at least one display, and in some cases even dual displays. Unfortunately, there is not an adapter that will add DP-Alt mode to a port that doesn’t natively support it.

      Hope this helps!

  14. Jan 3 years ago

    Hi, I’d like to connect my iPhone 5 (lightning) to a portable monitor that has usb-c connector (ASUS MB16AC). Is there any way to output a video from iPhone into usb-c? Actually the monitor requires power via the same one usb-c connector so I would need some kind of usb-c splitter to be able to supply power as well. Any tip is appreciated.

    • Danielle 3 years ago

      Hi Jan. Your ASUS MB16AC display requires a source that has USB-C out with DP Alt Mode. Alternatively it will work with computers that have USB-A ports, provided they are running one of the displays supported operating systems. Unfortunately, at this time, there is not a way to convert your Lightning connection to USB-C with DisplayPort.

  15. David Johnson 3 years ago

    Hey I was wondering if my gaming laptop only has a usb-c port and my monitor supports 144hz only with DisplayPort 1.2 if I got a usb-c to DisplayPort 1.2 adapter the 144hz would work on external monitor
    Try to email me the answer if possible

    • Danielle 3 years ago

      Hi David! We have emailed you regarding your question. Thanks!

    • carlos 3 weeks ago

      Hi! I got exactly the same question.
      Found this question on the forum
      De you have the answer?

      • Danielle at 3 weeks ago

        Provided your computer supports DisplayPort over USB-C (DP Alt mode), you can achieve 144Hz refresh rate on capable DisplayPort monitors using a USB-C to DisplayPort 1.2 cable or adapter. It is important to note, the bandwidth of the cable will be limited to the standards of DP1.2. Thus, the higher the refresh rate, the lower the achievable resolution. For example, most of our USB-C to DisplayPort 1.2 cables and adapters can handle 4K @60Hz, or alternately 1080p @144Hz.

  16. Scott 3 years ago

    I am trying to send video out from my display port on my laptop to my docking station. My docking station uses a USB C input. My monitors connect to my docking station. Is there a cable with a male connector that I can connect my laptop and USB C male connector I can connect to my docking station?

    • Danielle 3 years ago

      Hi there! There are some details we’ll need to clarify to help find a solution. A representative from our technical support team will be reaching out to you to provide further assistance.

  17. Bart 3 years ago

    Hello to all!
    My question:
    I need a thunderbolt 3 cable of 2m (6 foot) that support (DP ALT) mode for USB-C at full dataspeed.

    I read somewhere that the only TB3 cables that could support full dataspeed have to be active (not passive). But those active cables doesn’t support (DP ALT) mode for USB-C.

    Is this true? Kind regards, B.

    • Danielle 3 years ago

      Hi Bart! Thanks for your question. Our technical support team has reached out to you directly to help clarify.

  18. Alex 3 years ago


    I’m about to purchase a Dell S2719DC Monitor which includes a USB C input which supports DP Alt Mode.

    Is it possible to connect the DisplayPort on my AMD Radeon RX480 graphics card to the USB C input on the monitor with a DisplayPort to USB C cable?

    • Danielle 3 years ago

      Hi Alex! Unfortunately our Type-C to DisplayPort products are not Bi-Directional so they would only work with Type-C on the host and DisplayPort on the displays. As the display can support up to 2560×1440 at 60 Hz, we would recommend the DP2HD4KS and then an HDMI cable to take advantage of the HDMI input on that display. Hope that helps!

  19. Danny 3 years ago

    Hello, I am looking for confirmation of my findings. I have a X99 Taichi motherboard

    I have six 4K monitors connected and I am trying to use the NVIDIA surround display option on 3 of the screens. But unfortunately, NVIDIA only allows 1 accessory display monitor/port. Now I read to still be able to use the other 3 monitors with the 3 monitors in the NVIDIA surround configuration, you need to use onboard video. Well my motherboard doesn’t have onboard video :-/ so I was trying to use the USB-C port to display the 2 remaining monitors. But I cant seem to get them to display through the StarTech adapter (MSTCDP122HD). I think my motherboard does not support the DP Alt Mode over USB Type-C. Any help would be greatly appreciated.

    • Danielle 3 years ago

      Hi Danny!

      It is very possible that the X99 Taichi motherboard may not support DP Alt Mode with MST over USB-C. If this is the case, then the MSTCDP122HD will not function properly. We recommend contacting the manufacturer and asking if multiple displays are supported through the USB-C port to confirm. If the manufacture confirms that this should work, then make sure to check the monitor resolutions, as the highest supported resolution through the MSTCDP122HD is 3840×2160 @ 30hz.

      Please feel free to reach out to our technical support team directly for more help and troubleshooting. We’re available via phone at 1-800-265-1844 or live-chat.


  20. Harley 2 years ago

    I was having a terrible time trying to connect a Surface GO, and a Note8 (Pie) to a M169AC+ – no usb-c to usb-c cable appeared to work (I even bought an Anker Powerline cable to test) until I managed to find the original cable – once I plugged it in it just worked on both devices – successfully triggering DeX on the Note8. Is there something special about DP Alt mode that requires a certain type of cable ?

    • Danielle 2 years ago

      Hi Harley,

      We recommend, first and foremost, ensuring that the USB-C cable supports video. Second, it looks like the monitor you mentioned above may be powered by the USB-C port which means that you’d also require power delivery. The previous cables you tried may not have supported these features. A cable like USB31C5C1M may be a good option for what you’re looking for.
      I hope this helps a bit.
      Please feel free to reach out to our Technical Support team directly if you have any other questions or concerns about your specific configuration.

  21. Steve 2 years ago

    i have an HP envy 13 with usb 3.1 type c that supports displayport 1.2 and i want to connect it to my external monitor, it has vga input, however i bought a usb c to vga adapter and it didnt work, this article says it can be done, did i buy the wrong adapter or what? any help is appreciated

    • Danielle 2 years ago

      Hi Steve – Our team will be reaching out to you directly to help!

  22. Mike Giovaninni 2 years ago

    We have seen an issue with the Intel NUC systems where the display connected to USB-C will disconnect from the system, and only remedy is to disconnect the cable and in some cases, restart the NUC. We have been using StarTech USB-C adapters to convert from both USB-C to HDMI as well as USB-C to DVI. In those cases where we have had Display Port available on the monitors, we have seen fewer issues with USB-C to Display Port adapters. We’ve updated the USB-C firmware on th NUC’s to no avail. Intel thus far has been about as much help as a whip socket on a jeep.. Any suggestions? (Monitors so far has been mostly Planar PLL and PXN series displays, but we’ve also seen it with other brands.

    • Danielle 2 years ago

      Hi Mike. Thank you for bringing this to our attention. Our team has reached out to you directly to try to help troubleshoot.

  23. David 2 years ago

    Hi, I want to build an ITX PC and use a portable display so that it’s relatively easy to carry around. I picked a graphics card with USB-C port on it, this means I can safely assume that it supports DP Alt mode and I can connect my display to my graphics card right?
    This is the graphics card I’m referring to:

    • Danielle 2 years ago

      Hi David,
      Our team tested this on an Asus RTX 2070 Dual to a Dell U2518D over USB-C to DP-Alt mode. It worked fine in this scenario so we believe it should work with yours. If not, please reach out to our technical support team.

  24. Hani Ghannam 2 years ago

    I have an Asus ROG mobile and i recently bought this promate unihub c4 that is supposed to allow screen mirroring to a larger monitor. It doesn’t seem to be working, is there anything i am missing on here or is it just that the mobile doesn’t support this type of transfer over cable

    • Danielle 2 years ago

      Hi Hani! Thanks for checking out our blog. We recommend contacting your phone’s manufacturer (ASUS) to help you troubleshoot.

  25. Phone Number 2 years ago

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  26. Ryan 2 years ago

    Hey I was wondering, my gaming laptop only has a usb-c gen 1 port and my monitor supports 144hz only with DisplayPort 1.2, if I got a usb-c to DisplayPort 1.2 adapter will I be able to get the 144hz to work on my external monitor?
    Try to email me the answer if possible please!

    • Matthew Shaw 2 years ago

      Hello Ryan,

      If your laptop has USB-C but it’s USB 3.1 Gen 1, it’s likely that the port only supports data and won’t work with video adapters. However, we’d be happy to help you look into this to confirm if it is compatible. Please contact us directly at where our Technical Advisors are available 24 hours a day, 5 days a week to provide assistance.

      Matt, Support

  27. David Painter 2 years ago

    I have a laptop dock with DisplayPort 1.4 and HDMI, I need a cable/adapter solution to take the video signal from one of those video outputs to a USB-C only monitor. Anything???

    • Danielle 2 years ago

      Hi David! Unfortunately, at this time we do not have an available solution however we will be releasing CDP2DP2MBD which should work. With that said, you would need to ensure that your monitor doesn’t have any USB hub ports and has a separate power supply.

  28. Mark 2 years ago

    This seems like it’s the reverse of what would be useful…

    Is there any way to encapsulate a USB port into a DisplayPort cable — the same way you can with audio? This would make it really easy to have a display, mouse, and keyboard with a single cable.

    This is how built-in USB ports on monitors should work – just use the DP cable for the connection instead of a separate USB cable.

    • Danielle 2 years ago

      Hi Mark! At this time there is no way to combine a data signal into a DisplayPort cable as DisplayPort uses a specific standard. However, there are new monitors available that are doing what you’ve described using USB-C where they draw power, video, and USB data through a single USB-C cable connected to a PC.

  29. David Painter 2 years ago

    Thanks, I’ll keep an eye for it, here is my situation in case you have any other thoughts…

    Thinkpad Ultra Docking Station (40AJ) and a ThinkVision m14 USB-C only monitor. The M14 works fine connected directly to the ThinkPad X1 Carbon Laptop, but no USB-C alt-c passthrough from the docking station when connected.

    It looks like I have to connect through DisplayPort or HDMI connection on the Dock for video out, but have not found a cable that can do that. This is where you product listed above will come into play.

    Funny, all Lenovo product setup that there is no factory solution for 🙁

  30. KEVIN 1 year ago

    I also have an HP ENVY from 2016 and an HP USB C to vga and it keeps telling me “Display connection might be limited”

    • Danielle 1 year ago

      Hi Kevin! Is the adapter working after the error? If not, it could indicate that the USB-C port on the HP is data only. If it is, it could just mean that the drivers on the HP need updating.

  31. HC 1 year ago

    Most user manuals don’t even mention DP ALT MODE and many on manufacturer chat support don’t know either . It’s bit of a crap shoot what works on USB-C and what doesn’t and what docking stations will support a connection to USB-C (data/video output). Take Lenovo:

    …anyone’s guess.

    • Danielle 1 year ago

      We understand how frustrating this can be which is why our team is here to help and provide any guidance we can. Our Technical Advisors are available 24hrs Mon – Friday via chat or phone (1 800 265 1844).

  32. Tranat 1 year ago

    I have some question please, i want to buy external monitor like thinkpad M14 with usb-c who need Alt MODE.

    Actually i have one laptop (lenovo y520-ikbm with gtx1060) , he has one usb 3.1 type c gen 1.

    I have one normal monitor 144hz (acer predator XB241HBMIPR)
    This monitor work very well on 144hz with cable from >> monitor DP cable to >> mini DP port on my laptop

    This same monitor work very well on 144hz from >> monitor DP cable to >> laptop port 3.1 usb-c gen 1

    That suppose the Alt Mode work with My port 3.1 usb-c gen 1 ?

    I Try to see the pdf documentation from My lenovo y520-ikbm but no information about Alt Mode on the usb-c.

    Thanks alot for your feedback

  33. Tranat 1 year ago

    Ty for your feedback and ur help. Have Nice day

  34. Douglas 1 year ago

    Hi Danielle,

    I need to get a monitor for my wife’s HP Elitebook X360 1030 G2, which has a 7th Gen Kaby Lake i5-7300U CPU& 620 on board GPU. The documentation for the notebook computer does not mention whether the USB-C is also a Thunderbolt 3 port. When I purchased the notebook it was sold as having Thunderbolt 3. I was told by HP that the USB-C port did have Display port capability. But I did not verify Alt Mode. Their is a Thunderbolt icon next to the USB-C port. The generation of the USB-C configuration would be I presume 3.1 as the two other USB 3.1 rectangular ports are listed as 3.1. I don’t think the second generation USB-C was available to Kaby Lake Gen 7 Intel CPUs either, .Besides buying a monitor and hoping for the best, is there anyway I can check whether the port is a thunderbolt port? As I presume if it is Thunderbolt, it will be able to talk to a USB-C monitor and also accept keyboard data from the monitor, as well as charge the notebook (if the monitor has that docking capability). Or I could purchase a Thunderbolt to USB-C powered hub, but I would still not know if the notebook is definately Thunderbolt. Sorry for the long post …

    • Danielle at 1 year ago

      Hi Douglas! Those are great questions – we understand all of this can get confusing. The HP Elitebook X360 1030 G2 does have Thunderbolt capabilities from the USB-C port and will have DisplayPort Alt Mode. Therefore, you will be able to use USB-C cables to connect directly to a USB-C monitor or use a USB-C docking station to access monitors and USB support. Hopefully, that helps to clarify things.
      If you have any further questions about your solution, please don’t hesitate to utilize our free tech support. Our team of technical advisors are available 24hr (Mon-Fri) to answer all of your tech and solution related questions. You can reach them via live chat at or by phone at 1-800-265-1844.

      • Saby 1 year ago

        Hi Danielle. I have an HP Pavilion X360 i7 running on Windows 10 64 bit. I have tried using a USB C to HDMi adaptor to connect to an external monitor but it doesnt seem to work. The driver seems to be registered under yje Device Driver.
        I then tried a USB 3 to HDMI adaptor. This too does not work. When I tested on an older i5 Samsung laptop it works fine even up to 3 ecternal laptops.
        Note: my x360 has no problem displaying externally through its HDMI port. It has an onboard intel graphics card and an additional NVIDIA 940 MX graphics card on board built in.
        Any advice would be great. Or any addon adaptor or workaround I could use.
        The USB C port works fine for data.
        I could not find any documentation on whether the USB C is Display Alt.

        • Danielle at 1 year ago

          Hi Saby! Our team has reached out to you to provide assistance. We hope that helps!

  35. Douglas 1 year ago

    Thanks Daneille. I have read lots about the Thunderbolt port and connecting it to a powered hub, and then going to a monitor or monitors. And the best solution is Startech. If one wants to run two monitors without bandwidth limitations, then the best solution is to buy a Thunderbolt receiving hub and then go from the hub to both monitors IMO. And those monitors will be much a very large amount less costly if not equipped with Thunderbolt, and still a lot less costly than a monitor with USB-C input. Its much cheaper to buy a monitor that just has HDMI-2 or Display port inputs. And while many USB-C monitors have the capacity to power a notebook, many do not, and also, the wattage output varies – some will only output 5w. Some 30w, some 45watt, some 60 watt. For two monitors the Startech powered hub with Thunderbolt input seems a lower cost solution by some considerable margin, despite the cost of the Startech hub. You get what you pay for though.

    • Danielle at 1 year ago

      Our docking stations and adapters can definitely solve your problem and provide an effective solution. If you need any help finding the right product, you can connect with our Tech Support or check out our docking stations page for lots of great tips and insights to help you find the right solution for your needs.

      • Markus 1 year ago

        I have an Asus USB-C only monitor that works good on my laptop and on my smartphone. The smartphone battery is therefore rapidly empty. So I have the idea to use a USB hub and connect a power pack, the monitor and the smartphone to it. Will that work? Do startech have any hub for this solution?


        • Danielle at 1 year ago

          Hi Markus! You may have success connecting your USB-C display to your laptop and phone while charging the laptop and phone using our CDP2DPUCP which allows a USB-C power connection. You will need to pair a bi-directional USB-C to DisplayPort cable between this adapter and your display. Something like CDP2DP2MBD will work.
          If you need any other support enabling this solution, please reach out to our free tech support team at They’re available 24hrs, Monday – Friday.

  36. Sora 1 year ago


    I have a similar question to Tranat.
    I read the manual of my computer (MSI GE63VR 7RE) and it says that I have Port USB 3.1 (Type C). But no other clarification.

    I want to buy a second monitor: ThinkVision M14. I read that monitor works with USB-C (DisplayPort 1.2 over Alt mode). Does it work with my computer?

    Thank you,

    • Danielle at 1 year ago

      Hi Sora! Our team did some research and reviewed the product manual for the device. They noticed that the DisplayPort Alt Mode (and Thunderbolt 3 support) is referenced as ‘optional’ and therefore we feel it may be best to reach out to MSI support to confirm if video is enabled on your particular computer.

      • Sora 1 year ago

        Hi Danielle, thank you for your answer! I asked MSI support and they told me that my computer didn’t have the USB C DisplayPort Alt Mode (and Thunderbolt 3 support) but only a USB C 3.1 Gen2.

        So I thought of another solution. First, some people say that a USB C to HDMI adapter doesn’t work. But then what about a USB C to Mini DisplayPort adapter?

        Also, on the same website, someone said that an adapter “USB 3.0 out of the laptop to the USB-C on the external monitor” works. The same person says that USB C to Mini DisplayPort works too. But I have doubts. What do you think?

        • Danielle at 1 year ago

          Hi Sora!
          Thank you for confirming the functionality of the Type-C port on the MSI computer. As it does not have DisplayPort Alt Mode, a Type-C to mini-DisplayPort (or DisplayPort) solution will not work with this computer.

          A USB adapter that uses a chipset to render display will likely work but it will require drivers as video signals are not native to the USB protocol. This is why the report of the USB 3.0 adapter worked – it’s not relying on the video pins/signals on the Type-C output itself.

          Douglas – great suggestion! A direct connection to a video port on the computer (HDMI or mini-DisplayPort) should work and would bypass the need for a USB solution. It is possible that the GeForce GTX 1060 supports MST, which may allow multiple displays to be available off the one port (and a USB port for powering the hub potentially).

          We recommend reaching out to our Technical Advisory team for one-on-one support to find a solution that will work with your setup.

          • Sora 1 year ago

            Thank you Danielle and Douglas for your detailed answers. I contacted your Technical Advisory team and they provided me with solutions. That would be for example to use an adapter to provide a DisplayPort connection from the computer and then use a bi-directional USB-C to DisplayPort cable to make the video connection to the monitor (but I still need an adapter DisplayPort to mini DisplayPort). And it needs another source of power from the second USB C (on the ThinkVision M14) because HDMI and Mini-DisplayPort connections coming from the PC would not be able to provide the required power.
            So it’s two cables, and I would like to avoid that. So for now I found another portable monitor that works with just one cable. The quality is a bit worst but it’s okay for my needs (at least for now).
            Have a nice day to both of you!

  37. douglas 1 year ago

    Sora, it sounds like your USB-C port is not thunderbolt. Hence it’s capacity is more limited.

    But you haven’t got a problem:
    1x Type-C USB3.1 Gen2 ; 3x Type-A USB3.0 ;1x RJ45 ; 1x SD (XC/HC) Card Reader ; 1x (4K @ 60Hz) HDMI ;1x Mini-DisplayPort

    Just connect using your displayport or HDMI. Your graphics controller spec is:
    Maximum Digital Resolution2
    DP 1.43, HDMI 2.0b, Dual Link-DVIDP 1.43, HDMI 2.0b, Dual Link-DVI Standard Display Connectors
    YesYesMulti Monitor

    You can run lots of monitors of that graphics card. For second monitor, you could daisy chain of one of the monitors, or just go direct to the second monitor with our spare graphics outlet port ie hdmi or displayport. Their might be a dock to aid simplicity of docking.

  38. Zoltán 1 year ago


    how to find out, which dp alt mode (1.2 or 1.4) my monitor supports? The monitor is an LG 32UD99, but i didn’t find this information on their website, i even asked their support, but they couldn’t answer to this question. The product site says: C type USB: x1, PD, DP Alt. Mode, Data, ver3.1 Gen1, UHD@60Hz, PD=60W.
    The monitor has a dp 1.2 port by the way, but i’m curious if it supports dp 1.4 through its usb-c port? I’d rather use this instead of the hdmi port i currently use.
    How could i find this out without buying a bidirectional dp 1.4 usb-c cable?

    Thank you for your help

    • Danielle at 1 year ago

      Hi Zoltán!

      Our team did some research and found that the specifications from LG indicate that both DisplayPort and USB-C connections are available, so the best solution to connect the monitor will depend on the available ports on the computer you are connecting to. We’d like to gather additional information from you regarding your setup and what specifically you’d like to achieve from the solution so we recommend contacting our Technical Support team directly for 1 on 1 live support. They can be reached 24hours (Monday to Friday), at

  39. Thomas 1 year ago

    DisplayPort outputs do support older DP 1.0/1.1 displays too. Is this also the case with USB-C/TB3 alt mode? Is it possible to connect a DP1.1 display to a USB-C output with a passive USB-C to DP cable? Or is DP1.2 the minimal requirement to trigger DP alt mode on an USB-C/TB3 port?

    • Danielle at 1 year ago

      Hi Thomas!
      Yes, USB-C and Thunderbolt 3 alt mode do support older DisplayPort standards as well. There is no requirement on the DisplayPort version of the display for this to work. However, if you want the features of DisplayPort 1.4 (like HBR3, HDR, 8K) you will need a DisplayPort 1.4 display that supports all those features.
      With that said, if your computer only has USB-C, not Thunderbolt 3, you’ll need to check if it supports DP alt mode.
      We hope that helps! If you have any other questions, please reach out to our Technical Support Team at

  40. Christopher Catallo 1 year ago

    How do i know if my mobile suppory alt mode

    • Danielle at 1 year ago

      Hi Christopher! We suggest reaching out to your phone manufacturer for a full breakdown on capabilities of your device.

  41. Ana 1 year ago

    How can I check if this feature is available on host PC

    • Danielle at 1 year ago

      Hi Ana! It’s best to consult the user manual and documentation included with your Laptop/computer as that will outline what each port on the machine will do. Aside from that, you can also contact the laptop manufacturer to ask directly.

  42. Jorge 1 year ago

    Hello Danielle,

    I have a HP Omen X 17-ap0xx gamer laptop, which has a 2x – USB-3.1 Gen 2 ports. I was wondering if your brand usb-c to displayport cable (which im planning to buy here: – in Chile-) will work for 165 Hz (or at least 144 Hz) on an Asus Gamer Monitor VG278QR. I asked to the store but they just answered me that I “should read the specs of the cable”. Can you e-mail me the answer?

    Thanks in advance and greetings from Chile!

    • Danielle at 1 year ago

      Hi Jorge!

      Thank you for contacting After looking into your Laptop model HP Omen X 17-ap0xx we have found that it should have two Thunderbolt 3/USB-C with DP ALT mode ports on the rear which means your laptop should be able to send a video signal through them. You may want to confirm this by referencing the user manual that came with the laptop or contacting HP support to ensure your model has this functionality from those ports, as some models have more features on the USB-C ports than others.

      If those ports are capable of outputting video then yes, our CDP2DPMM1MW will work with your Asus VG278QR monitor at 1920×1080 @144Hz and @165Hz as you were hoping! This is a DisplayPort version 1.2 cable meaning it will even work at more demanding resolutions, up to 2560×1440 @165Hz or 4K @60Hz should you ever want upgrade in the future.

      If you have any other questions or concerns please feel free to contact our support team at where we would be happy to assist further.

  43. Carlos V 1 year ago

    Hi! I own an HP envy x360, and want to connect to my LG monitor 34um69G-B. Both of them have usb-c, and I believe both of them allow dp alt.

    My question is: Could I just buy a usb-c to usb-c cable, with no adapter? I currently have an hdmi to hdmi, but my monitor only have one of hdmi port and want to release it to connect my xbox.

    Thanks in advance for any help!

    • Danielle at 1 year ago

      Hi Carlos! Our team looked into this and it looks like your monitor supports DP-Alt mode, so what you’re proposing should work. With that said, your HP Envy x360 may not, therefore you will need to check if it also supports DP-Alt mode. If it does, then again a USB-C cable that lists video support, such as USB315CC2M, would work.

  44. GAMALIER HERNANDEZ 1 year ago

    hello I have an Acer A515-51G-83QA laptop, and I purchased this adapter ( for my Samsung SF350 monitor, not knowing about ALT mode. It turns out that it did not work for me, due to the problem (“The screen connection may be limited”).

    The question is, is there any connector either “normal” USB or USB type C where I can connect my laptop to my monitor ???

    Note; the HDMI port is already occupied for 1 additional monitor. so look for USB type C to connect this second screen.

    Or can I just update my laptor to one that does have usb type C Alt Mode Display?

    greetings and thank you very much I stay tuned.

    • Danielle at 1 year ago

      Hi Gamalier! Unless you were already planning to, there is no need to upgrade the computer if all you want to do is add a second external extended monitor.

      Assuming you are working with Windows, we recommend the USB32HD4K as a good option to connect the Samsung monitor to the Acer computer. The USB32HD4K does require driver installation but will get you up and running with a second external extended monitor.

      It does not appear to be possible to use a USB-C based adapter since specifications from Acer lists the USB-C port on this product as being data only, no video. This function is not normally upgradeable.

      We hope that helps!

  45. Matt 1 year ago

    Hi, I want a cable to connect my Lenovo ThinkVision M14 portable display to my late 2018 Mac Mini with suitable USB-C cable.

    My question is: What sort of USB-C cable, would be sufficient to do the job?

    Fortunately I know my computer is compatible with the monitor because I successfully tested the connection with a 0.5m StarTech Thunderbolt 3 cable. It works well.

    I could buy another thunderbolt 3 cable but this is overkill because I only need a USB-C cable with support for DP1.2 alt mode and DP2.0. Hence my question.

    Some other relevant details:
    1. the Lenovo M14 is designed to only work with a USB-C cable (for data and power). It requires DisplayPort (DP1.2 alt mode) and power over USB (PD2.0).
    2. My Mac mini supports DP1.2 and power over USB with USB-C connectors via its Thunderbolt 3 ports.
    3. No drivers are required and the M14 is operating-system independent.

    Thanks in advance.

    Also, if you have any thoughts on the following this would be appreciated. There was a cable supplied with the monitor. I expected it to work with my computer, but in my testing it only works with *some* computers that meet the requirement of having DP1.2 and PD2.0 on USB-C. It does not work with my Mac Mini.

    • Danielle at 12 months ago

      Hi Matt! Our Tech Advisors have reached out to you directly to help. If you need further assistance please feel free to reach out to us at

  46. Vikrant 1 year ago


    My monitor : Hp elite 237q – here are the specs
    It has a usb c port with power delivery upto 15W. ( So it won’t charge my MacBook Air with PD :/ )

    My MacBook Air 2018 retina – has following specs from the manual:
    1. Thunderbolt 3 digital video output
    2. Native DisplayPort output over USB‑C
    3. VGA, HDMI, and Thunderbolt 2 output using adapters (sold separately)

    Two Thunderbolt 3 (USB-C) ports with support for:
    Thunderbolt (up to 40 Gbps)
    USB-C 3.1 Gen 2 (up to 10 Gbps)

    The question is…
    Can my Mac support display port Alt Mode over usb c ?
    I have two options to connect my air with monitor –

    1. Buy a usb c to usb c cable ( usb c 3.1 gen 2 – this is written on packaging of the cable ) – I’m hoping this usb c to usb c ( usb 3.1 gen 2 implementation ) send display port video over usb – c cable ( How should I confirm this ? )

    2. Buy a usb c to display port cable . ( USB c on one end and display port on the other end of the cable )

    Which one should I go for and which one is better.

    Thanks in advance
    Will be eternally grateful to all of you 🙂

    • Danielle at 1 year ago

      Hi Vikrant!

      Either a USB-C cable or USB-C to DisplayPort cable will work to connect your display to one of the Thunderbolt 3 ports on your MacBook Air. Neither of these options is really better or worse as they should perform with the exact same technical capability.

      Here are a couple options that will work with each scenario:

      6ft. USB-C cable: USB315C5C6
      6ft. USB-C to DisplayPort cable: CDP2DPMM6B

  47. Ty 1 year ago

    Which usb-c to hdmi adapter will work with a Blackberry Keyone?

    • Danielle at 1 year ago

      Hi there!
      Unfortunately, based on what our team could find, the Keyone doesn’t support DisplayPort Alt Mode. It would be best to check with the manufacturer to confirm this.

  48. Yvette Jackson 1 year ago

    could anyone please help me – I have a school issued HP ProBook 360 for my visually and hearing impaired daughter. We are trying to connect it to two external monitors so she can use one for her zoom class sessinos and the other screen to do her work while staying on zoom (extend desktop, not mirror). I’ve tried to plug her HP ProBook into my HP G2 dock station and get an MHT error message (also her USBC isn’t working to charge her HP ProBook either). I’m trying to troubleshoot to find out if this is just a general USBC port problem (she also has bluetooth error on this so maybe the whole laptop needs replacement) or if I need a different kind of adapter to work to connect more than one monitor (she only has one HDMI out port on the Probook). Our school’s tech team is overwhelmed and in the meantime I have a girl who can’t see her screen 🙁 Also, we tried an alternate school issued Chromebook and while it worked with my HP G2 docking station, I couldn’t get the two external monitors to extend (they just mirrored each other while the laptop showed the different display..not helpful since the screen is too small on the laptop). Any help would be appreciated. I’d be happy to give you further sales if someone could maybe just help a girl who is in desperate need of better visual aid.

    • Danielle at 1 year ago

      Hi Yvette! We’re sorry to hear you’re experiencing these issues! Our team would be happy to help you. Please reach out to our Technical Advisors at or 1-800-265-1844. We’re available 24hrs a day, Monday to Friday.

  49. Hello 11 months ago

    I have a usb-c only Asus portable monitor, however, some of my laptops do not have a usb-c port.
    I could get a bi-directional DisplayPort to USB-C cable, however, this cable would not supply power to the monitor.
    Is there a solution for combining USB-C Alt-Mode(no power) with USB-C PD power into one cable to operate this monitor?

    • Danielle at 11 months ago

      Hi there! We recommend reaching out to our Tech Advisors directly. They’ll gather a little more information from you to ensure they’re making the best recommendation for your solution. We’re available 24hrs, Monday to Friday, at or 1-800-265-1844. You can also find more resources at

  50. Bert 11 months ago

    Hello! First of all: Thanks for giving support to all this confused consumers here.

    Can I drive a LG 34WL850-W on my Apple Macbook 12″ (early 2016)?
    The Macbook supports DP Alt Mode over USB-C but not Thunderbolt.
    LG mentions Thunderbolt 3 support over USB-C as well as having dedicated DisplayPort Connector.
    So far the LG Support was unable to 100% confirm that I will work.

    The macbook only has this single USB-C port so the monitor has to provide power to the macbook, drive the display and function as a USB-hub for my peripherals (which works fine with my current Lenovo ThinkVision P27u)

    • Danielle at 11 months ago

      Hi Bert!

      Unfortunately, it looks like the computer you use won’t support that display. Judging by the specs, it looks like it supports up to one 4K display (3840×2160) at 30 Hz, however, the bandwidth and resources needed to drive the monitor are more than what the computer can handle.

      The monitor resolution is 3440×1440 60Hz which uses 8.92 Gbps of bandwidth, 4K 30Hz uses 7.46 Gbps. If you are willing to lower the refresh to 30Hz, then that may be a solution.

      Additionally, the monitor won’t charge the laptop, it simply doesn’t support that feature. You could possibly try CDP2HDUACPW which will add one HDMI port, one USB 3.0 port, and a USB-C port for charging only, so you can still charge the computer while the display is connected.

      We hope that helps! If you have any other questions, please feel free to reach out to our Advisors at

  51. toarsapada 11 months ago

    Hi, i’m wondering if your team maybe can test and confirm if there’s one of your bi-directional DP to USB C cables can work for this scenario:

    Laptop’s DP port connect to Thinkvision M14 USB C.
    Understand that DP to USB C cable do not deliver power, but i assume that we can use M14 other USB C port connect to power source.

    • Danielle at 11 months ago


      After reading the user manual of the portable display, page 10 shows an example of charging the display while getting video from another source. Therefore, this looks like it could work, however, we cannot test to confirm. If you have any other questions, please feel free to reach out to our Advisors at

  52. mackenzie 11 months ago

    I am trying to connect either a USB-A, or HDMI port device (acer chromebook r11) to a USB-C Monitor (acer pm161q) and am having troubles. From what I found online there is no way to work around this, but was wondering if you had any solutions. Below are the two devices:

    – Acer Chromebook R 11 Convertible Laptop, Celeron N3060, 11.6″ HD Touch, 4GB DDR3L, 32GB eMMC, C738T-C7KD

    – Acer PM161Q bu Portable Monitor 15.6″ Full HD (1920 x 1080) (USB Type-C for Video/Power & Micro USB for Supplemental Power

    • Danielle at 11 months ago

      Hi Mackenzie!

      Unfortunately, we do not have a solution for this.

      Because the monitor states that the micro USB is only for supplemental power, we believe this means that it gets most, if not all, of its power from the USB-C. If this is the case, it would require a USB-C port for the power needs as well as video. Unfortunately, we do not have a 1 cable or adapter solution that converts the video and adds power. If you have any other questions, please feel free to reach out to our Advisors at

    • Alan 7 months ago

      Hi there,

      I have this a Dell wd19 k20a docking station which connects to my Dell laptop by usb c with DP alt mode. If I upgrade my laptop with one that has thunderbolt usb c. Can I use it with my old dock or does this need to support thunderbolt too?

      Cheers Alan

      • Danielle at 6 months ago

        Hi Alan! Seeing as this is a Dell product, we suggest reaching out to their support for the most comprehensive answer. They’ll have more information on their product and if it will work with your new laptop.

  53. Christian Hill 7 months ago


    I have an Asus VivoBook S14/S15.

    I currently have 1 additional monitor connected using the HDMI port.

    When looking on “Device Manager” under “Universal Serial Bus Devices” it does show a “DisplayPort ALT mode device”.
    So I should be able to connect a second monitor using the USB-C connection, by purchasing a USB-C to HDMI adaptor and connecting to the second monitor that way.

    Is that correct?

    Thank you

    • Danielle at 3 months ago

      Hi Christian! Unfortunately, we don’t expect this to work as neither manual references DisplayPort or Alt-Mode. If you’d like to contact us and provide a model number, however, we may be able to help you find a solution.

  54. Paul 7 months ago

    My Thinkpad T14s (Intel) has one USB-C (charging) port and one Thunderbolt 3 port. I used several USB-C docks now and I only get 2x1080p on both ports. But I need 1x1440p + 1x1080p. Are my USB-C ports limited to DP 1.2? Thank you!

    • Danielle at 6 months ago

      Hi Paul! We recommend reaching out to the manufacturer of your device for clarification on this.

  55. Peter A Alexandris 3 months ago

    So I have an HP Laptop 14-dq1xxx and I have one monitor connected to my HDMI port and I tried connecting a second monitor via USB-C but I got a notice stating limited mode on USB-C. How can I make my laptop capable of allowing display over USB-C? Do I need some sort of adapter to make it happen? I tried connecting to a docking station and plugged the dock into the USB-C port as well but i got the same message. I want to be able to connect 2 monitors to my laptop but it seems its not possible. Any advice? I can provide the specs of my computer if needed.

    • Danielle at 3 months ago

      Hi Peter!
      The warning you are seeing is from Windows, this pop-up happens when the computer detects an adapter that tries to use capabilities the computer does not have. For example, not all USB-C ports support DisplayPort Alt Mode (video output), so plugging a USB-C video adapter in will trigger this message from the operating system and no video will pass through the adapter.
      The good news is there are ways around this using adapters that require drivers. We recommend contacting our support directly and they can help make sure you get the right product for your specific setup. Please visit

  56. Alan Revell 2 months ago

    I have an Asus MB169C+ with DP Alternate support on its USB-C connection which I use as a second laptop display. I regularly need to use industrial PCs which have DVI video outputs on, is it possible to get adaptors to convert the PC’s DVI output to USB-C Alt mode video signal (only 1080p) for use with my portable screen? I’m struggling to find anything out there… Many thanks for your help.

    • Danielle at 1 month ago

      Hi Alan! The Asus MB169C+ only has a single USB-C port on it, which it uses for both video and power. Unfortunately, at this time, we do not have an adapter that combines power and video input into a USB-C connector. We would suggest contacting Asus to see if they have any, or are aware of any adapters like this.

  57. Peter UBERTO 1 month ago

    I have a different conundrum to discuss. I have an ASUS TUF A15 gaming LAPTOP with a NVIDIA 2060 GPU.
    The GPU has two USB 3.2 Gen 1 Type A ports and one USB 3.2 Gen 2 Type C DP 1.4 port.

    I bought a Oculus RIFT A Virtual Reality ( VR ) headset system that uses one USB Gen 1 Type A cable and one DisplayPort.1.2 or 1.4 cable. I have tried three different DisplayPort to USB Gen 2 adapters But no Video
    or Audio gets sent to the Headset.

    What are your recommendations as far as an adapter . Also I believe ALT Mode has to be also considered.
    Thanks in advance.

    Peter U.

  58. Mike 4 weeks ago

    Could really use a hand. I recently purchased a Dell G15 5511 laptop. The spec sheet about the usb c port indicates that it is a:

    Thunderbolt 3/USB 3.2 Gen 1 Type-C port with DisplayPort with alt mode

    I have not been able to get video to output to my Dell AW3418DW 34″ Ultrawide. Having tried:

    – a USB-C > Display Port cable
    – a USB-C > Display Port adapter from my local computer shop
    – a Dell USB-C > Display Port adapter from

    The first two items in that list only returned that a “billboard” usb device was hooked up. The Dell adapter shows as a display port alt mode device on the eject usb icon. But still no video displays on my monitor.

    I have hooked up the laptop with the dell adapter to other monitors using other cables and still no luck.

    Any advice would be appreciated.

    • Danielle at 3 weeks ago

      Hi Mike! Based on the specifications of your computer, any standard USB-C to DisplayPort cable, such as our CDP2DP146B, could connect your monitor. There are several reasons you may not be getting a picture, including but not limited to the monitor input and display settings. I would recommend trying one of our USB-C to DisplayPort products, and if you run into any difficulties reach out to speak with our expert technical advisors and we would be happy to help get you up and running!

  59. Adrian Harris 4 weeks ago

    I have some Samsung devices i use as a laptop replacement (namely a s8 plus) and want to move to my note 10. I also have a dp alt mode compatible external screen. They both work fine directly connected.

    My problem is finding a dock/dongle that supports dp alt mode pass though, with a 3.5 audio jack.

    The note doesnt have a audio jack.

    • Danielle at 3 weeks ago

      Hi Adrian! We have a few options that may work to connect your displays to both phones using DP Alt mode and add the additional 3.5mm jack. Check out our DK30CHDPD. The right product for you will depend on the model of your displays. Feel free to contact us directly via live chat and one of our expert advisors would be happy to direct you to the most compatible product!


  1. […] refresh rate 75Hz yang membuat gerakan tidak mulus. Kelebihan dari monitor ini hanya mendukung Mode Alt DisplayPort yang menjadi bagian […]

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