nadkarni@ashok.dec.com (12/04/89)
Anyone out there used the HD controllers from PERSTOR ? I was wondering if they are worth the additional $125 or so over a WD1006 type controller. In particular, do they really work with MFM (non-RLL) drives reliably ? Is the disk capacity increased significantly ? Throughput ? Most important, how compatible are they ? Would OS/2 get confused by this type of controller ? I have a ST225 and a Quantum 530 that I'd like to use in an AT I'm putting together and thought their performance would be more reasonable with this controller. Thanks, /Ashok Nadkarni
akcs.larry@nstar.UUCP (Larry Snyder) (12/04/89)
>Anyone out there used the HD controllers from PERSTOR ? I was wondering if >they are worth the additional $125 or so over a WD1006 type controller. >In particular, do they really work with MFM (non-RLL) drives reliably ? The throughput on the Perstor controllers will average 1/3 that of the WD1006V-SR2. If you want speed - the Perstor is a mistake - if you want space - then maybe the Perstor is what you need.
khc@eecea.eece.ksu.edu (Ken Carpenter) (12/05/89)
I formatted a Miniscribe 3085 using the Perstor HD controller last August. It gave the 1.9 times capacity as advertised, but could not run at 1:1 interleave, requiring 2:1 instead (on a 16MHz 386 box). It ran without error until the board died about 6 weeks later. I replaced it with the WD1006V-SR2. This controller can run at 1:1 interleave and so gives transfer rates about a factor of two higher. However, the Miniscribe could not be used with it. The Miniscribe 3085 reported errors on about one of 10 tracks when formatted using the WD RLL controller, where it had reported none using the Perstor. Further, the bad tracks changed randomly when one repeated the test scans. Trying to use it led to such behaviour as being able to load a file to it, but then not be able to read it back immediately, even with most of the tracks marked bad. The conclusion: MS3085 won't support RLL. The question: how is it able to support ARLL?
Ralf.Brown@B.GP.CS.CMU.EDU (12/05/89)
In article <897@eecea.eece.ksu.edu>, khc@eecea.eece.ksu.edu (Ken Carpenter) wrote: > >I formatted a Miniscribe 3085 using the Perstor HD controller last August. [then reformatted with a WD1006V-SR2 and had lots of problems] >The conclusion: MS3085 won't support RLL. >The question: how is it able to support ARLL? First, ARLL has different timings than RLL, which probably affected things. Second, the Perstor uses mondo error correction, but still has significantly higher rated hard-error rates than MFM drives. -- UUCP: {ucbvax,harvard}!cs.cmu.edu!ralf -=-=-=-=- Voice: (412) 268-3053 (school) ARPA: ralf@cs.cmu.edu BIT: ralf%cs.cmu.edu@CMUCCVMA FIDO: Ralf Brown 1:129/46 FAX: available on request Disclaimer? I claimed something? "How to Prove It" by Dana Angluin 13. proof by reference to inaccessible literature: The author cites a simple corollary of a theorem to be found in a privately circulated memoir of the Slovenian Philological Society, 1883.
plim@hpsgpa.HP.COM (Peter Lim) (12/06/89)
> > Anyone out there used the HD controllers from PERSTOR ? I was wondering if > they are worth the additional $125 or so over a WD1006 type controller. > In particular, do they really work with MFM (non-RLL) drives reliably ? > Is the disk capacity increased significantly ? Throughput ? Most important, > how compatible are they ? Would OS/2 get confused by this type of controller ? > I have a ST225 and a Quantum 530 that I'd like to use in an AT I'm putting > together and thought their performance would be more reasonable with this > controller. > Here's my brief experience with PERSTOR controller. First let me mention my setup. One PERSTOR controller (probably an older model, but then I don't have any reference). 25 MHz no cache '386 with AMI bios (which means can set bus speed to either 12.5MHz, 8.33MHz or 8MHz), 8MB RAM. One old Seagate ST225 harddisk (probably not very good one). Okay, the bottom line is that I can't run the system at 12.5MHz bus speed; so losing about 50% bus performance. Second, I think I need to insert one wait state in the bus operation, a further speed reduction. After getting everything working, I get about 250 KB/sec transfer rate by CORETEST which is about the same as normal MFM controller. The 40MB MFM drive was formatted to 78MB and I lost about 1.5MB to bad sectors. After setting up, I ran Norton's Disktest every now and then and had so far discovered another 4 to 5 clusters of bad sectors (no big problem, right ? :-)). Another annoying feature is that the damn thing kept getting calibration error and have to rewind the harddisk every 10 minutes or so. Well, for me, I am not using the PERSTOR, no way ! Actually, I was just borrowing it as a temporary stop gap till my ESDI harddisk arrive (which is today). Regards, Peter Lim. HP Singapore IC Design Center. E-mail address: plim@hpsgwg.HP.COM Snail Mail address: Peter Lim Hewlett Packard Singapore, (ICDS, ICS) 1150, Depot Road, Singapore 0410. Telephone: (065)-279-2289