Xref: utzoo comp.sys.amiga.tech:6060 comp.sys.amiga:36398 Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!apple!usc!ucla-cs!uci-ics!zardoz!tgate!ka3ovk!drilex!axiom!linus!mbunix!rachamp From: rachamp@mbunix.mitre.org (Richard A. Champeaux) Newsgroups: comp.sys.amiga.tech,comp.sys.amiga Subject: Re: ST296N Interleave (was Re: Pal, Jr. HD controller info needed) Summary: My HardFrame gets me 655K reads and 291K writes with the ST296N Message-ID: <58224@linus.UUCP> Date: 3 Jul 89 18:50:37 GMT References: <727@orbit.UUCP> <759@censor.UUCP> Sender: news@linus.UUCP Reply-To: rachamp@mbunix (Champeaux) Organization: The MITRE Corporation, Bedford, Mass. Lines: 65 In article <759@censor.UUCP> hugh@censor.UUCP (Hugh D. Gamble) writes: >In article <727@orbit.UUCP>, baxt@pnet51.cts.com (Bill Backstrom) writes: >... >> I have a B2000 with a 2090 and a ST296N (85 meg SCSI). I'm running >> 1.3, definitely using FFS (512 byte blocks) and version 34.4 of >> hddisk. >> >> Diskperf gives me a reads of about 80K bytes/sec and writes of 155K >> bytes/s for 32K blocks. I've also had an ST125 (20 meg ST-506) on the >... >> I have tried different interleaves, another 2090 card, and various >> partition sizes. Nothing has improved the performance. The only >... >> Bill Backstrom > >You probably need an interleave of 4:1 for that drive. I recall >a post a while back on C.S.A where someone said he'd managed to >get optimal performance on a ST296N at 3:1 interleave, but it took > >I have a 2000 with a 2620, and a 296N on a Comspec SA2000 non-DMA >SCSI controller. On a stock 2000 Comspec recommends an interleave of >5:1 for the 296N and that comes as the default. >I found I now get optimal performance (diskperf around 250K/s for >reading & writing) with an interleave of 4:1. > >It seems that the ST296N needs a peculiarly high interleave for >either controller. I haven't the faintest idea why. Any guesses? > >that makes it different from most drives, but a user issue to note >that if you have one or get one you can expect best results with a high >interleave. ... >Hugh D. Gamble (416) 581-4354 (wk), 267-6159 (hm) (Std. Disclaimers) That's Funny, I have a HardFrame 2000 and a ST296N and diskperf is telling me that with 32k buffers, I'm getting 655K reads and 291K writes. The sheet that came with the drive said that it could handle an interleave of 1 and the manual for the HardFrame said to use an interleave of 1. Actually it said it was fast enough to keep up with all drives and to use an interleave of 1 for all drives. I was using GVP's Impact2000 before, a non-DMA controller. It was giving me some rather depressing transfer rates. I was only getting 120k reads and writes. This really annoyed me because my Supra 20 Meg drive for my 1000, was getting 143K reads and writes, and that was with a 65 ms drive. GVP's software didn't let you change the interleave for the drive, but the HardFrame's format program told me that the drive had been formatted with an interleave of 1. I might have gotten decent transfer rates with the GVP if it had only let me change the interleave. GVP's installation software might be easy to use, but it lacks things like not being able to set the interleave. With a non-DMA controller, that's very important. It didn't even come with a park utilitiy. Thank God the 296N is an auto parking drive. While I was waiting for my 296N, I thought about putting in my miniscribe 20 Meg, but when I didn't see a park command, I called GVP to ask how to park the drive. They said they were working on a program but they hadn't finished it yet. I though it was kind of curious that they didn't have a park command, since the miniscribe 8425S was on the list of drives they said work with the Impact 2000. The 8425S has to be parked before moving it and if you can't park it, you're pretty much screwed. Anyhow, I'm supprised that the 2090 and the 2090a aren't blazing along with the 296N. It's a fairly fast drive, but a DMA controller should be able to keep up with it without any problem. Rich Champeaux (rachamp@mbunix.mitre.org)