USB3 (wasMoving an HD from one comp to another)

[Tyler Aviss]

So if you connect a USB2 device to a computer's USB3 bus, does it work
happily without crapping out the CPU, or only enable DMA/interrupt for
USB3 enabled devices?

I haven't bought any USB3-enabled boards yet. What's the state of
linux-friendliness of the controllers. I know i've had a lot of USB2
devices that would drop-off on various boards in 'nix but not in
windows for some reason...

On Thu, Nov 25, 2010 at 3:32 PM, Lennart Sorensen
<lsorense-1wCw9BSqJbv44Nm34jS7GywD8/FfD2ys at public.gmane.org> wrote:
> On Thu, Nov 25, 2010 at 01:27:23PM -0500, William Muriithi wrote:
>> Was very grateful to learn this when it was posted a while back.
>> Explained why whenever I am offloading some data from the server to an
>> USB drive, it always tend to trigger high load nagios alert.  Its even
>> odd that USB 2 using polling instead on interrupts
>>
>> That said, it looks like they have fixed both the lack of DMA and
>> interrupts  with USB 3.  I have just scanned through USB 3
>> specification and I wonder if I got this fact right
>
> I would hope so.  I highly doubt they could pull off 4.8Gbit/s without
> DMA.
>
> For USB1 it was OK.  For USB2 it was a crappy design choice (Firewire
> already had DMA done right which is why 400 and 800Mbit/s firewire works
> great with very little CPU load).
>
> --
> Len Sorensen
> --
> The Toronto Linux Users Group.      Meetings: http://gtalug.org/
> TLUG requests: Linux topics, No HTML, wrap text below 80 columns
> How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists
>



-- 
Tyler Aviss
Systems Support
LPIC/LPIC-2/DCTS/CLA

“It can takes months to gain a customer, but only seconds to lose one"
--
The Toronto Linux Users Group.      Meetings: http://gtalug.org/
TLUG requests: Linux topics, No HTML, wrap text below 80 columns
How to UNSUBSCRIBE: http://gtalug.org/wiki/Mailing_lists