Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!sun-barr!lll-winken!uunet!mcsun!ukc!dcl-cs!aber-cs!athene!pcg From: pcg@cs.aber.ac.uk (Piercarlo Grandi) Newsgroups: comp.unix.sysv386 Subject: Re: benchmarking SCSI host adapters Message-ID: Date: 10 Nov 90 17:41:25 GMT References: <1686@chinacat.Unicom.COM> Sender: pcg@aber-cs.UUCP Organization: Coleg Prifysgol Cymru Lines: 42 Nntp-Posting-Host: odin In-reply-to: chip@chinacat.Unicom.COM's message of 9 Nov 90 04:09:11 GMT On 9 Nov 90 04:09:11 GMT, chip@chinacat.Unicom.COM (Chip Rosenthal) said: chip> I have in my hot little hands two SCSI controllers - an Adaptec chip> AHA-1542B and a BusTek BT-542B. I've been trying to do some chip> benchmark comparisons of the two using the "bonnie" program. chip> [ ... ] chip> I was told the BusTek gives about 3X the performance of chip> the Adaptec. I'm not seeing this - I see 1X performance. [ ... around 300KB/sec per block IO, read or write ... ] chip> For reference, these were run on SCO ODT 1.0 (with no kernel chip> tweaking). Ahem. SCO Unix uses a fast file system of some sort, but from the numbers you show I would guess that either the SCSI driver or the filesystem are not as efficient as they could. I have seen better numbers for the Adaptec than those you give. chip> how useful is "bonnie" for disk system benchmarking? Totally useless. "bonnie" tests for IO system performance -- the disk subsystem is only the back end of an IO system. It is difficult to abstract the performance of the disk subsystem from that of the whole IO system, and probably pointless. chip> Right now, my guess is that either I was given marketing performance chip> numbers for the BusTek card rather than real performance numbers, or any chip> additional performance of this card is just wasted potential on this 20MHz chip> machine. Unless your IO system sw is CPU bound (and this is quite difficult, even if not totally impossible), and your numbers show that doing block IO CPU intensity is 40-50%, CPU speed is not that important with an intelligent controller. Setting it up properly and having an efficient driver and filesystem implementation are far more important as limiting factors. -- Piercarlo Grandi | ARPA: pcg%uk.ac.aber.cs@nsfnet-relay.ac.uk Dept of CS, UCW Aberystwyth | UUCP: ...!mcsun!ukc!aber-cs!pcg Penglais, Aberystwyth SY23 3BZ, UK | INET: pcg@cs.aber.ac.uk