Re: [E1000-devel] Slower performance on E5 than i7?

[Waskiewicz J. P. P <pet...@in...>]

On Fri, 2013-09-20 at 20:51 -0700, Ben Greear wrote:
> We have been seeing across-the-board network performance issues
> with the E5 2643 v/s an I7-980.
> We've been trying ixgbe, igb, and 'veth' virtual devices.
> 
> Driven by user space or pktgen, the E5 is usually slower by
> a noticeable bit.  We did disable the VTD BIOS thing that really
> kills performance, but perhaps there are other BIOS things we
> should tune in the E5 system?
> 
> We tried various kernels back to about 3.0 and the general
> slowness remains.
> 
> Has anyone done similar comparisons and seen issues?

If I'm not mistaken, the E5 has a lower max frequency than the desktop
parts.  What I suspect is you're seeing your workloads physically run
faster on the I7 due to turbo pushing the core past 3 GHz, but the E5 I
think hovers in the 2.5-3.0 range.

Other factors could be how memory is populated in both systems.  Are you
sure all channels are populated in both systems?

This is just some of the quick low-hanging fruit I can think of now.

Cheers,
-PJ