Date: Wed, 15 Apr 1998 09:39:47 -0400 From: sbabkin@dcn.att.com To: tarkhil@asteroid.svib.ru, dyson@FreeBSD.ORG Cc: hackers@FreeBSD.ORG, smp@FreeBSD.ORG Subject: RE: SMP performance decrease? Message-ID: <C50B6FBA632FD111AF0F0000C0AD71EEACDEB1@dcn71.dcn.att.com>
next in thread | raw e-mail | index | archive | help
> ---------- > From: John S. Dyson[SMTP:dyson@FreeBSD.ORG] > > Alexander B. Povolotsky said: > > Hello! > > > > I've just benchmarked (by bytebench from ports) my new server, with > 64M RAM > > (for now; will increase soon) and 2 PII-233 processors (EliteGroup > p6LX2-A > > mainboard). > > > > Here are the results: > May be some description of tests can help: > > > > Test Non-SMP SMP > > arith (double) 27.5 28.1 > This test is running in one process so it hardly can show anything. An interesting modification would be to run 2 parallel processes. > > Drystone 2 (no reg. vars) 23.6 24.1 > The same. The speed gain may be because other processes that are running in background are using the second processor now. > > Execl thoughput 90.8 46.8 <- ??? > I can't remember about this > > File copy 35.1 37.7 > Also single-threaded. > > Pipe-based context switching 20.4 9.0 <- ??? > Two processes and a pipe, passing 1 byte each time in alternating direction. The number of bytes passes is supposed to be the same as the number of context switches. In fact, the processes here are running _not_concurrently_, they are synchronized by byte passing. So the speed can hardly be higher, but should not be twice slower either until there is high interprocessor synchronization overhead compared to context switch overhead (provided that FreeBSD context switch overhead is really low, that may be the case). > > Shell scripts (8 concurrent) 12.8 12.2 <- ??? > 8 shell scripts are running concurrently. This is supposed to simulate 8 users running. And think that this is a somewhat weird result. Serge To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message
Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?C50B6FBA632FD111AF0F0000C0AD71EEACDEB1>