[SOLVED] Why do GPUs have USB ports?

Why does the entire line-up of Nvidia 2000s have USB Type-C? What is the point of a USB port on a GPU?

https://www.anandtech.com/show/13268/custom-geforce-rtx-2080-quick-look

Could it be for VR?

Well, USB 3.1 Gen1 is 5 Gbit/s and Gen2 is 10 Gbit/s. Is that enough bandwidth? I don’t think it is. The Vive and Rift run at 2160x1200 with minimum of 90Hz. That is 7 Gbit/s at 8 bit per pixel, if the color depth is 16 bit/pixel then you need 12.6 Gbit/s. Vive and Rift been out a while now, I’d expect new headsets with higher resolutions and faster refresh rates, within the lifetime of Nvidia’s 2000s right?

Anyway idk, I haven’t found any concrete answers yet…

Your thoughts?


they are not using the usb protocol

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Thanks, that uhhh answers all my questions… [Solved] then?

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It’s USB Type-C in either DisplayPort (as shown in the screen capture above) and/or VirtualLink alternate mode.

https://www.anandtech.com/show/13088/virtuallink-announced-standardized-connector-for-vr-headsets

VirtualLink supports

  • DisplayPort up to 32.4 Gbps - 4x HBR 3 channels, so up to 4K120; and
  • USB 3.1 Gen 2 (10 Gbps)

at the same time. Additionally it is able to supply power to a VR headset.

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Yup, that is what it is. Its a new type of port designed for VR.

We know VR is going to require VR headsets with MUCH higher resolutions. Already the Pimax 8KX is on the way which will, unlike the Pimax8K, not just have a 4K display for each eye but also have 4K video input for them. With the regular Pimax I think it will get something like 2K input for each eye, and then it will be upscaled to 4K, the benefit I think will be less of a screen door effect or SDE. Which is the problem with being able to see spaces between the pixels. Personally I do not see that as a problem with the Rift, but that might be due to its color bleeding problem, so… :stuck_out_tongue:

But the reason I got into all of that is that the Pimax 8KX has a BIG problem… being able to get 2 4K video feeds from the computer, to the HMD at 90fps. 90fps is what is said to be needed in a VR headset to avoid… well at least new users getting motion sickness. As it is right now I think they have opted to just aim for 60fps and then use some tricks that might make it feel like more.

This new VR cable though would solve that problem, at least if they can find a way to make the Pimax 8KX support this cable… then the next problem just is whether it will be possible to actually run games in this high a resolution without melting? Eye tracking and foveated rendering is probably going to help with that though.

you’ll find USB in alot of busses, mini pcie has USB as well fx.
basically the daisychaining, and usb support for display ports is why it takes no effort from the developer to just convert a port to a USB port.feks
simply filter out the non usb signal, which is all standardized.

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