Date: Fri, 11 Oct 2002 16:59:13 -0700 From: Terry Lambert <tlambert2@mindspring.com> To: Cheng Jin <chengjin@cs.caltech.edu> Cc: freebsd-smp@freebsd.org, Xiaoliang Wei <weixl@cs.caltech.edu> Subject: Re: SMP + dual GbE Message-ID: <3DA765D1.D6C4B92C@mindspring.com> References: <Pine.LNX.4.33L0.0210111539380.29183-100000@fast2.cs.caltech.edu>
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Cheng Jin wrote: > We are currently working on a high-speed TCP project. We have a couple of > machines built on supermicro's P4DP6 board each with two 2.4 Ghz Xeon > processors and two GbE cards from SysKonnect. We were able to get close to > 1 Gbps throughput(loopback tests) on RedHat Linux 7.3 SMP kernel > (2.4.18-3) with interrupt moderation on the GbE cards (5000 interrupts/s) > and binding one CPU to each card. > > However, under FreeBSD SMP, we have only been able to achieve about 640 > Mbps on each card. I suppose the binding of CPU to card is implicit (?) > under FreeBSD SMP since we didn't notice any out-of-order packets. We > tried interrupt moderation going as high as 10,000 per second and as low > as 2500, but that didn't seem to help much. Furthermore, we were able to get > about 560 Mbps throughput for each card under a single-processor kernel so > it seems that the extra processor didn't help much under SMP. > > We don't know a whole lot about how SMP works under FreeBSD. Actually, we > don't know anything about FreeBSD SMP. Any comments/suggestions are > greatly appreciated. It may be your SysKonnect card. It's very easy to get full wire speed with 1500 MTU packets on an 800MHz machine with Tigon III cards (for example). It's all in the tuning. See previous threads in the FreeBSD-net mailing list archives for more information. -- Terry To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-smp" in the body of the message
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