shatara@memit.dec.com (Chris Shatara) (08/20/89)
I'm wondering if I should rerun SCSI Timer and SCSI Hacker on my hard disk to optimize the interleave for the faster scsc driver in V5.0. Does this make sense or is the speed basically limited by the scsi interface card and drive? I have already optimized the interleave under V4.0 with a 40% improvement in read times and was wondering if the interleave should change because of the SCSI driver improvements in System 5.0 Any thoughts or comments? /chris ============================================================================= | Chris Shatara | Internet: shatara@memit.dec.com | | | shatara@memit.enet.dec.com | | Opinions expressed are | DEC Easynet: memit::shatara | | mine and mine only! | UUCP: ...!decwrl!memit!shatara | =============================================================================
prl3546@tahoma.UUCP (Philip R. Lindberg) (08/24/89)
From article <661@mountn.dec.com>, by shatara@memit.dec.com (Chris Shatara): > I'm wondering if I should rerun SCSI Timer and SCSI Hacker on my hard disk > to optimize the interleave for the faster scsc driver in V5.0. > > Does this make sense or is the speed basically limited by the scsi > interface card and drive? This is a very interesting question. I have a homebrew hard drive so I ran these routines when I put mine together. I assumed that they optimized to the hardware only, and then when I did the highlevel formatt with the ADU it did any optimization for the operating system. If this is true, then rerunning these should not make any difference. So my question would be: is there any advantage to redoing a highlevel formatt under V5.0? (I would guess not.) > I have already optimized the interleave under V4.0 with a 40% improvement > in read times and was wondering if the interleave should change because > of the SCSI driver improvements in System 5.0 When you reran these and got a 40% improvement was it because you changed the interleaf? (Or maybe it was because of the driver/ADU improvements in V4.0?) (I really am asking. I'm not trying to put words in your mouth. I would like to know since I formatted my drive under version three.) > /chris +---------------------------------------------------------+ | The Apple //'s will live forever!! | | Phil Lindberg snail mail: 13845 S.E. 131 ST | | INET: prl3546@tahoma.UUCP Renton, WA 98056 | | UUCP: ..!uw-beaver!ssc-vax!shuksan!tahoma!prl3546 | | Disclaimer: I don't speak for my employer (and I not | | sure they even know I exist....) | +---------------------------------------------------------+
shatara@memit.dec.com (Chris Shatara) (08/27/89)
# ## I have already optimized the interleave under V4.0 with a 40% improvement ## in read times and was wondering if the interleave should change because ## of the SCSI driver improvements in System 5.0 # #When you reran these and got a 40% improvement was it because you changed #the interleaf? (Or maybe it was because of the driver/ADU improvements in #V4.0?) (I really am asking. I'm not trying to put words in your mouth. I #would like to know since I formatted my drive under version three.) # The improvement was from the interleave. The reason I say this Is that I ran the disk for a month under V4.0 BEFORE I got a copy of SCSI hacker and Timer. I never ran the hard disk under System software V3.2. I just finish this procedure again with new system disk. As before I ran a while with the old interleave settings and by changing them was able to reduce the read times by another 15% (according to SCSI timer). Interesting enough the docs which came with SS 5.0 suggested 1:1 or 1:2 as an interleave setting (infact the software would use one of these settings if you allowed it to do the low level format) I ended up with a setting of 5. (4 gave me the lowest setting and 5 gave me some margine for tolerances). I am running with an Apple SCSI board and a SEAGATE st138N drive. /chris ============================================================================= | Chris Shatara | Internet: shatara@memit.dec.com | | | shatara@memit.enet.dec.com | | Opinions expressed are | DEC Easynet: memit::shatara | | mine and mine only! | UUCP: ...!decwrl!memit!shatara | =============================================================================
prl3546@tahoma.UUCP (Philip R. Lindberg) (08/29/89)
From article <707@mountn.dec.com>, by shatara@memit.dec.com (Chris Shatara): > # > ## I have already optimized the interleave under V4.0 with a 40% improvement > ## in read times and was wondering if the interleave should change because > ## of the SCSI driver improvements in System 5.0 > # > #When you reran these and got a 40% improvement was it because you changed > #the interleaf? (Or maybe it was because of the driver/ADU improvements in ^^^^^^ I wrote this question. ^^^ > The improvement was from the interleave. The reason I say this Is that I > ran the disk for a month under V4.0 BEFORE I got a copy of SCSI hacker and > Timer. I never ran the hard disk under System software V3.2. I'm sorry, I'm still confused. Does this mean you didn't format your drive originally to the optimum interleaf using a SCSI Timer (or compat.)??? Therefore, your improvement was from doing this? > I just finish this procedure again with new system disk. As before I ran > a while with the old interleave settings and by changing them was able to > reduce the read times by another 15% (according to SCSI timer). When you say "old interleaf settings" do you mean "the Apple defined" settings? (ie. 1:1 or 1:2) Or do you mean "your previously optimized" settings? (ie. optimized at, say, 9 with 4.0, and now 5 with 5.0) > Interesting enough the docs which came with SS 5.0 suggested 1:1 or 1:2 as > an interleave setting (infact the software would use one of these settings > if you allowed it to do the low level format) I ended up with a setting > of 5. (4 gave me the lowest setting and 5 gave me some margine for > tolerances). I am running with an Apple SCSI board and a SEAGATE st138N > drive. The Apple doc.'s suggestion really only apply to APPLE's stuff. Any one with a third party drive (including homebrew) must use the optimum for their config. The third party manufacturers figure this out for you. If you have a homebrew, you need to do it yourself. (Note: the Seagate ST138N is a fast 30 meg. drive. If you ran with Apple's default interleaf it's no wonder you got a big improvement.) > /chris +---------------------------------------------------------+ | The Apple //'s will live forever!! | | Phil Lindberg snail mail: 13845 S.E. 131 ST | | INET: prl3546@tahoma.UUCP Renton, WA 98056 | | UUCP: ..!uw-beaver!ssc-vax!shuksan!tahoma!prl3546 | | Disclaimer: I don't speak for my employer (and I not | | sure they even know I exist....) | +---------------------------------------------------------+
shatara@memit.dec.com (Chris Shatara) (09/01/89)
> >> The improvement was from the interleave. The reason I say this Is that I >> ran the disk for a month under V4.0 BEFORE I got a copy of SCSI hacker and >> Timer. I never ran the hard disk under System software V3.2. > >I'm sorry, I'm still confused. Does this mean you didn't format your >drive originally to the optimum interleaf using a SCSI Timer (or compat.)??? >Therefore, your improvement was from doing this? > Correct. I ran the first month with whatever interleave the disk had out of the box, probably 1:1 as the dealer I bought it from also sells the drives for the mac. I didn't get a copy of Timer until about 4 weeks later. >> I just finish this procedure again with new system disk. As before I ran >> a while with the old interleave settings and by changing them was able to >> reduce the read times by another 15% (according to SCSI timer). > >When you say "old interleaf settings" do you mean "the Apple defined" >settings? (ie. 1:1 or 1:2) Or do you mean "your previously optimized" >settings? (ie. optimized at, say, 9 with 4.0, and now 5 with 5.0) I mean my previously optimized settings under 4.0 . System Software 4.0 4.0 5.0 5.0 interleave stock $C $C 5 READ value 90 62 91 50 > >(Note: the Seagate ST138N is a fast 30 meg. drive. If you ran with Apple's I'm really delighted with it and V5.0....nice machine! ============================================================================= | Chris Shatara | Internet: shatara@memit.dec.com | | | shatara@memit.enet.dec.com | | Opinions expressed are | DEC Easynet: memit::shatara | | mine and mine only! | UUCP: ...!decwrl!memit!shatara | =============================================================================