From: Chris Friesen <chris.friesen@genband•com>
To: Alexander Duyck <alexander.h.duyck@intel•com>
Cc: "J.Hwan Kim" <frog1120@gmail•com>, netdev <netdev@vger•kernel.org>
Subject: Re: intel 82599 multi-port performance
Date: Tue, 27 Sep 2011 16:57:33 -0600 [thread overview]
Message-ID: <4E8254DD.6020908@genband.com> (raw)
In-Reply-To: <4E820486.4090204@intel.com>
On 09/27/2011 11:14 AM, Alexander Duyck wrote:
> This more or less confirms what I was thinking. You are likely hitting
> the PCIe limits of the adapters. The overhead for 64 byte packets is too
> great and as a result you are exceeding the PCIe bandwidth available to
> the adapter. In order to achieve line rate on both ports you would
> likely need to increase your packet size to something along the lines of
> 256 bytes so that the additional PCIe overhead only contributes 50% or
> less to the total PCIe traffic across the bus. Then the 2.5Gb/s of
> network traffic should consume less than 4.0GT/s of PCIe traffic.
For some further information, according to the information here:
http://shader.kaist.edu/packetshader/io_engine/benchmark/i3.html
a dual-port 82599 controller with an i3 CPU can in fact handle sending
*or* receiving (and then dropping) full line rate on both ports for
minimum-sized packets. It can't do both though. The CPU used in tose
tests isn't the greatest however, so it's tough to say where the
bottleneck is.
Chris
--
Chris Friesen
Software Developer
GENBAND
chris.friesen@genband•com
www.genband.com
next prev parent reply other threads:[~2011-09-27 22:59 UTC|newest]
Thread overview: 14+ messages / expand[flat|nested] mbox.gz Atom feed top
2011-09-26 10:26 intel 82599 multi-port performance J.Hwan Kim
2011-09-26 14:20 ` Chris Friesen
2011-09-26 15:42 ` J.Hwan.Kim
2011-09-26 16:04 ` Alexander Duyck
2011-09-26 16:40 ` Chris Friesen
2011-09-26 17:24 ` [E1000-devel] " Ben Greear
2011-09-26 17:46 ` Chris Friesen
2011-09-26 17:57 ` Ben Greear
2011-09-27 0:45 ` J.Hwan Kim
2011-09-27 15:30 ` Martin Millnert
2011-09-27 17:14 ` Alexander Duyck
2011-09-27 22:57 ` Chris Friesen [this message]
2011-09-26 18:16 ` Rick Jones
2011-09-27 0:39 ` J.Hwan Kim
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