Re: [gentoo-user] 10 G eth (10000) on Gentoo

[Adam Carter <adamcarter3@gmail.com>]

> I just might have an opportunity to setup a Gentoo
> System using 10 G ethernet (fiber). The .39
> kernel lists this hardware [1].
>
> Does anyone have any experience with this hardware?
> Does it work? Did you make any bandwidth measurements?
> What type of fiber (mulimode/singlemode) (ST/SC) did you
> use?
>
> Any comments? Is the kernel a bottleneck or your application?

Intel are active in linux kernel development and their linux drivers
seem to be very good.

When testing Intel copper gig interfaces on an intel firewall (HP
DL380G5 8 core box), I was able to send a core to 100% with ~330Mb of
small packets. The limiting factor appears to be packet rate, and the
consequent processing of interrupts (1 irq to 1 core). I don't think
that a 10Gig interface would pass any more than that due to similar
limitations.

Tweaking the e1000 driver options RxDescriptors, TxDescriptors and
RxIntDelay pushed it up to ~350Mb. MSI was enabled so no interrupt
sharing.

So if you're running normal sized packets, you should be ok. Otherwise
you way want to look at what irqbalance can do for you (I didn't try
it at the time).

Also don't forget stuff like Large Receive Offload in your kernel.