Re: [LAU] hardware - Intel CPUs

From: Len Ovens <len@email-addr-hidden>
Date: Thu Apr 17 2014 - 02:33:55 EEST

On Wed, 16 Apr 2014, Jeremy Jongepier wrote:

> On 04/16/2014 10:51 PM, Len Ovens wrote:
>> It appears that the USB2 devices have problems with USB3 ports (Like the
>> 1818vsl).
>
> So far I have little issues with my USB2 audio interface (not a 1818VSL)
> and the xhci driver. I've come across that thread too and it seems the
> issue is specific for the 1818VSL.

It is specific to the Intel Ivy Bridge chipset USB3 implementation. So if
your computer uses a different HW implementation you should be fine. For
example a PCIe card with USB3 ports is ok or a MB that uses different HW.
Intel admits the problem is there but will not fix it and feels that well
written drivers will just ask the USB device for a resend of the missed
packet !!!??? They say that nobody will notice the missing packet
anyway??? I read this to mean "it is in the hardware now and there is no
soft/firmware patch possible." One hopes the 4th gen chips are better
designed. Thats what I am looking to buy. I don't have a USB2 device to
try though.

> I should really do some testing how the ehci and xhci drivers compare,
> at the moment I'm inclined to think either the USB3 host controllers I
> use or the xhci driver performs better with my interface than either
> USB2 controllers or the ehci driver.

That is at least good news. I suspect a HW difference in the host off the
top of my head. I think the system pays more attention to them too.

--
Len Ovens
www.ovenwerks.net
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Received on Thu Apr 17 04:15:02 2014

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