On Sun, Oct 11, 2015 at 10:31:13AM +0200, Tobias Nygren wrote:
> Hi!
>
> I am aware USB 3 is still experimental and barely supported on intel
> boards, but I wonder if anyone has investigated support for USB 3 PCI
> expansion cards? This would be useful to get USB 3 ports on old
> machines that don't have PCI-e.
>
> I have found cards online that use either the FL1000G chip or some
> Renesas chip, coupled with a pci-e to pci bridge. I believe both are
> supposed to implement xhci. Does anyone know which of these has the
> highest chance of working?
Either should work. I'm not aware of any USB 3 controller that isn't
XHCI. But obviously you'll have a bandwidth limit issue for SuperSpeed.
SuperSpeed is like 600MB/s, conventional PCI is only 133MB/s. Even
1st-gen PCIe x1 is only 2.5Gbit/s, half the bandwidth of a USB 3 port.
2nd-gen (5Gbit/s) PCIe x1 is really the way to go.
The xhci driver outside the nh-usb branch only supports USB 1 and USB 2.
I've not been following the xhci rewrite on the nh-usb branch.
Considering the extra cost of a bridged-to-Conventional-PCI XHCI board,
it might be more wise to find a machine with a PCIe slot. I'm not aware
of any XHCI chips that have a native Conventional PCI interface. Many
old and obsolete machines now have PCIe.
Jonathan Kollasch
