Re: [usb] usb 3.0 bandwidth insufficient

[Peter Geis]

On Thu, Feb 27, 2020 at 1:36 PM Toerless Eckert <address@hidden> wrote:
>
> I tried to get the NVidia 3D glasses IR emitter to work for windows 10
> in KVM (before NVidia F***ed with 3D fans and removed all support for
> it from their drivers). No performance, but low-latency USB signalling
> problem, delay through qemu was just miserable.
>
> I ended up buying a mini-PCIe USB3 card so that i had a separate
> PCI USB controller rom the one on the motherboard and then passed
> that PCI controller through to the VM. Works fine.
> (mini-PCIe was the only free slot on my mini-ITX MoBo).
>
> Would expect there is also no performance degradation when using
> passthrough.
>
> Cheers
>     Toerless

Unfortunately this isn't viable for me.
All I have is a bunch of 1x pcie 2.0 ports, which is also insufficent.
I'm about 100 mbps short with pcie 2.0.
Need the full 600+ mbps of usb 3.0.

Latency isn't as much of an issue.

>
> On Thu, Feb 27, 2020 at 12:39:04PM -0500, Peter Geis wrote:
> > Good Afternoon,
> >
> > I have been trying to pass through a usb capture card over usb 3.0 to
> > a windows vm.
> > The device requires 90% of actual usb 3.0 bandwidth, as it captures
> > native 1080p 60fps video.
> > Unfortunately it seems the qemu usb controller cannot provide this, as
> > the device fails to provide video at 1080p.
> >
> > I'm trying to find a way to debug this and have not had much success,
> > can anyone point me in a direction to check?