9 votes

How do I know if a USB-C PCIe card supports 4k video output?

finally getting to be that time where I need a USB-C slot on my tower that I built back in 2017 so I started looking into expansion cards.

One thing I can't tell is how to tell if a particular expansion card supports the usb-c ports with DP-Alt mode for a 4k display if the need arises.

for exmple, had my eye on this one and I can't tell much if it does have that kind of support

7 comments

  1. [4]
    cfabbro
    (edited )
    Link
    Amazon is generally pretty shit at listing tech specs of the products they sell... but the manufacturers' sites usually have them. E.g. Here is the StarTech product page for the card you linked to...

    Amazon is generally pretty shit at listing tech specs of the products they sell... but the manufacturers' sites usually have them. E.g. Here is the StarTech product page for the card you linked to which specifically says "Does not support DP-Alt Mode/USB Power Delivery".

    So my advice would be to work backwards from how you may usually do it. Hunt for a card that has DP-Alt support, then see if it's being sold on Amazon, if that's your preferred retailer. Rather than vice versa.

    p.s. The Sunix UPA2015 supports DP-Alt, but it's currently out of stock on Amazon and Newegg. However, it is available on eBay (same card since they're Dell's OEM).

    10 votes
    1. [3]
      b3_k1nd_rw1nd
      Link Parent
      wasn't aware that any USB-C PCIe card that support video output also need a port connection to my GPU...guess I am looking for just USB power delivery at this point.

      wasn't aware that any USB-C PCIe card that support video output also need a port connection to my GPU...guess I am looking for just USB power delivery at this point.

      2 votes
      1. [2]
        pallas
        Link Parent
        To put it another way: DisplayPort alternate mode literally sends DisplayPort signals through some pins on a Type C cable, instead of normal USB signals. So you need that DisplayPort signal to get...

        To put it another way: DisplayPort alternate mode literally sends DisplayPort signals through some pins on a Type C cable, instead of normal USB signals. So you need that DisplayPort signal to get to the port somehow.

        I've more commonly seen Type C ports on GPUs themselves.

        3 votes
        1. teaearlgraycold
          Link Parent
          That was around for one generation on nvidia 2000 series cards. Not sure if AMD did that as well.

          That was around for one generation on nvidia 2000 series cards. Not sure if AMD did that as well.

          1 vote
  2. [2]
    creesch
    Link
    Just be aware, most of these cards if they support it, you will likely need to pass through a display port connection from your GPU.

    Just be aware, most of these cards if they support it, you will likely need to pass through a display port connection from your GPU.

    6 votes
    1. b3_k1nd_rw1nd
      Link Parent
      ok, that I was not aware of. TIL. guess I am looking for usb power delivery mode only at this point.

      ok, that I was not aware of. TIL. guess I am looking for usb power delivery mode only at this point.

      2 votes
  3. arch_mage
    Link
    A ThunderBolt Addin card would work your use as case. Just be aware that the ThunderBolt spec is slightly different than DP-ALT mode. This in theory this shouldn't matter unless your device...

    A ThunderBolt Addin card would work your use as case. Just be aware that the ThunderBolt spec is slightly different than DP-ALT mode. This in theory this shouldn't matter unless your device specifically only works with DP-ALT mode. This brochure from Dell has good visuals of difference without getting too technical.

    About a year ago, I did something similar where I put my PC in a different room and with a single thunderbolt cable ran a 4K monitor (120Hz) with high speed USB through a ThunderBolt Dock.

    Something to note about ThunderBolt: motherboard vendors make their own cards and they usually aren't cross vendor compatible*.
    Here are links to ThunderBolt cards on their vendors website.

    *The Gigabyte Titan Ridge 2.0 has seen success working on different vendor motherboards, see this reddit thread for more details

    Some notes from my experience:

    • You need to enable a setting in the Bios which is under a different name for each motherboard vendor
    • Finding the thunderbolt drivers for windows is a nightmare. Linux has them baked into the kernel in recent versions
    • On windows you need to download this unsearchable app from the windows store to enable ThunderBolt.
    • Give up putting your computer to sleep. Wake from sleep is flakey at best. (I've heard that they improved this with ThunderBolt 5 but I haven't tried)
    • ThunderBolt stuff in general is poorly documented.