Xref: utzoo comp.unix.i386:6566 comp.sys.ibm.pc:53713 Path: utzoo!attcan!uunet!sjsca4!poffen From: poffen@sj.ate.slb.com (Russ Poffenberger) Newsgroups: comp.unix.i386,comp.sys.ibm.pc Subject: Re: Adaptec 1542 Kernel tuning with 386/ix Message-ID: <1990Jul6.151152.5316@sj.ate.slb.com> Date: 6 Jul 90 15:11:52 GMT References: <1990Jun29.230754.251@nstar.uucp> <361@zds-ux.UUCP> <1990Jul04.123903.3204@nstar.uucp> Reply-To: poffen@sj.ate.slb.com (Russ Poffenberger) Organization: Schlumberger Technologies, San Jose, CA. Lines: 30 In article pcg@cs.aber.ac.uk (Piercarlo Grandi) writes: > >In article <1990Jul04.123903.3204@nstar.uucp> larry@nstar.uucp (Larry >Snyder) writes: > > behm@zds-ux.UUCP (Brett Behm) writes: > > >I really do not know what to make of these results. > > I don't either. In all cases the tests were executed on the same > location on the disk - with NOTHING else running.. > >But you don't teel us the crucial details -- did you read from the raw >device, the block device, or from the filesystem? In the latter two >cases, how did you defeat the read-aheading. or ensured it was used, and >in the last ase, did you unmount/remount the filesystem before each read >to be sure to defeat the caching? > >All over I see transfer rates around 300K per second. If they are thru >the filesystem it is not too bad, but I had expected better from >AHA1542, HPDD, and FFS. Something more like 5000-600 KB/sec. I can get 1.3Mbytes / sec from an AHA1542B with a CDC Wren IV running dos. This is straight disk performance, not cached. Reads and writes are about the same. Russ Poffenberger DOMAIN: poffen@sj.ate.slb.com Schlumberger Technologies UUCP: {uunet,decwrl,amdahl}!sjsca4!poffen 1601 Technology Drive CIS: 72401,276 San Jose, Ca. 95110 (408)437-5254