liggio@cunixf.cc.columbia.edu (Vincent J. Liggio) (03/26/91)
I have a Quantum ProDrive 170S and an Adaptec 1522 controller (SCSI-2). Supposedly, I should be getting upwards of 2 MB/sec out of this combination, but when I use coretest (v 2.91), it tells me I am getting a mere 900 k/sec. The ProDrive has a 64k cache built in on board. Some system details: Mylex MXA-33, 386 33 mhz motherboard 8 mb ram Adaptec 1522 SCSI-2 contoller Quantum ProDrive 170S DOS 4.01 I called adaptec but they weren't helpful. They said call your dealer, since their dealers are supposedly knowledgeable about the card. Of course this didn't work. I checked out all the manuals, and I think that I have the zillion and one jumpers set correctly, but I am still sluggish. Any clues??? Any ways I can check on the cache being implemented (it goes on and off and changes sizes depending on the mode that the drive is running in). Vince Stallion Tigger +----------------------------------------------------------------------------+ | INTERNET : liggio@cunixf.cc.columbia.edu | | BITNET : liggio@cunixf.bitnet | | UUCP : {rutgers,topaz}!columbia!cunixf!liggio | +----------------------------------------------------------------------------+
iverson@xstor.com (Tim Iverson) (04/03/91)
In article <1991Mar25.161209.564@cunixf.cc.columbia.edu> liggio@cunixf.cc.columbia.edu writes: >I have a Quantum ProDrive 170S and an Adaptec 1522 controller (SCSI-2). >Supposedly, I should be getting upwards of 2 MB/sec out of this >combination, but when I use coretest (v 2.91), it tells me I am getting a >mere 900 k/sec. The ProDrive has a 64k cache built in on board. This is perfectly normal. The Quantum ProDrive 170S has a maximum sustained transfer rate of about 900KB/s. The burst rate can be much higher than that, but 900 is the best you'll ever get out of CoreTest. The 170S is actually just your average, every-day, middle of the road, mass-market drive. If you really want *fast* you should think about Imprimis' Elite (4-5MB/s) or Wren VII or Wren Runner (2-3MB/s). Of course, *fast* implies *bucks* :-). >| INTERNET : liggio@cunixf.cc.columbia.edu >| BITNET : liggio@cunixf.bitnet >| UUCP : {rutgers,topaz}!columbia!cunixf!liggio - Tim Iverson iverson@xstor.com -/- uunet!xstor!iverson
liggio@cunixf.cc.columbia.edu (Vincent J. Liggio) (04/03/91)
In article <1991Apr02.214925.10627@xstor.com> iverson@xstor.com (Tim Iverson) writes: >This is perfectly normal. The Quantum ProDrive 170S has a maximum sustained >transfer rate of about 900KB/s. The burst rate can be much higher than that, >but 900 is the best you'll ever get out of CoreTest. > >The 170S is actually just your average, every-day, middle of the road, >mass-market drive. If you really want *fast* you should think about >Imprimis' Elite (4-5MB/s) or Wren VII or Wren Runner (2-3MB/s). Of course, >*fast* implies *bucks* :-). > >- Tim Iverson > iverson@xstor.com -/- uunet!xstor!iverson Interesting, because the drive manual says that the drive can sustain 2.5 Mb/sec. And the adapter can do 5 asynchronous, 2.5 mb synchronous (or vise-versa). Doesn't sound like the middle of the road, mass market drive. Just a wee bit faster... :-) Vince
poffen@sj.ate.slb.com (Russ Poffenberger) (04/04/91)
In article <1991Apr3.015013.2129@cunixf.cc.columbia.edu> liggio@cunixf.cc.columbia.edu (Vincent J. Liggio) writes: > >In article <1991Apr02.214925.10627@xstor.com> iverson@xstor.com (Tim Iverson) writes: >>This is perfectly normal. The Quantum ProDrive 170S has a maximum sustained >>transfer rate of about 900KB/s. The burst rate can be much higher than that, >>but 900 is the best you'll ever get out of CoreTest. >> >>The 170S is actually just your average, every-day, middle of the road, >>mass-market drive. If you really want *fast* you should think about >>Imprimis' Elite (4-5MB/s) or Wren VII or Wren Runner (2-3MB/s). Of course, >>*fast* implies *bucks* :-). >> >>- Tim Iverson >> iverson@xstor.com -/- uunet!xstor!iverson > >Interesting, because the drive manual says that the drive can sustain 2.5 >Mb/sec. And the adapter can do 5 asynchronous, 2.5 mb synchronous (or >vise-versa). Doesn't sound like the middle of the road, mass market drive. >Just a wee bit faster... :-) > They are talking more about thoeoritical rates than actual rates. You can get these high rates if you happen to read from the cache on the drive. However the maximum rate you can peel off the disk is purely a function of how fast the bytes fly past the head. This is determined by the rotational rate (usually 3600 RPM for most drives, 5400 coming soon), and the number of sectors per track. If you read more data than the cache has in it, then the disk rate is what limits you. 900K/sec sounds reasonable. 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