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Path: euryale.cc.adfa.oz.au!newshost.anu.edu.au!harbinger.cc.monash.edu.au!nntp.coast.net!news.dacom.co.kr!bofh.dot!arclight.uoregon.edu!news.uoregon.edu!newsxfer2.itd.umich.edu!news.itd.umich.edu!naughty.monkey.org!pha From: pha@monkey.org (Paul H. Anderson) Newsgroups: comp.unix.bsd.freebsd.misc Subject: Fastest sustained SCSI disk speed Date: 20 Jun 1996 04:02:40 GMT Organization: University of Michigan Lines: 44 Message-ID: <4qaih1$ave@lastactionhero.rs.itd.umich.edu> NNTP-Posting-Host: naughty.monkey.org Keywords: disk speed scsi X-Newsreader: TIN [version 1.2 PL2] I'm starting to buy a bunch of equipment for the disk intensive portion of a compute server I'm setting up. Our application is similar in disk behaviour to desktop video - large sequential reads. I strongly prefer FreeBSD 2.1.0, and will be using 200MHz P6 machines, but initial testing is on a p5/120. I need to obtain rotational scsi drives that have the fastest possible sustained throughput through the FreeBSD filesystem (bsd ffs). Cost is not a concern, but I can't use RAM based drives, since I'd rather just put the RAM in with the CPU. Besides, I need the drives to act as cache for about 4-15GB of data, which means RAM drives are out of the question. I am planning on using an Adaptec Ultra Wide dual bus PCI controller card (3940UW, I think). I just looked at the code, and it appears to support this card. Is there a single SCSI drive that I can likely get greater than 10MB/second sequential reads through the filesystem sustained? Is there a better card than the adaptec? What kinds of speeds can I expect? To date, the best I've done on FreeBSD was about 4.5 MB/sec with an NCR FW SCSI controller and a 2GB baracuda drive on an older P5/90, which I was a bit disappointed with, actually. I'm hoping to get something set up that will do well over 10MB/sec. I guess I'm also interested in hearing about 2 drive RAIDS that may give 2X performance over a single drive without requiring a sector striping device driver. I recall hearing about striping in freebsd, but don't know the status of that. I have some money to play around with, so will be doing some experimenting of my own that I can report here if folks are interested. Any feedback would be greatly appreciated, and I will happily summarize any responses to others, either here, or by email. Email preferred, as it is difficult for me to keep up on this newsgroup. TIA, Paul Anderson pha@pdq.com