neese@adaptx1.UUCP (06/11/91)
>I have both an Adaptec 1540B and a DPT PM2001/95. I now use the DPT >board only. I have it connected to a Conner CP3200F, 200 Mb SCSI-2 >drive. In comparing the Adaptec to the DPT, I had some interesting >results. According to Core tests, for what they're worth, the DPT >delivered faster seek times (18.1 msec for the DPT vs. 19.2 for the >Adaptec). I attribute this to the fact that the DPT uses a faster >processor (MC68000, 10 MHz) and is a full 16-bit board meaning that all >data paths are 16 bit. This is not (I believe) the case for the 1540B - >it uses and 8 bit processor. >STUFF DELETED< The 154x is a full blown 16 bit adapter with a full blown 16 bit data path. The on board CPU is for local transactions only and has nothing to do with the actual data transfer. This is handled by the DMA chip and sequencer on the adapter board. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese
neese@adaptx1.UUCP (06/11/91)
>>>3) If I also upgrade with a new disk, 80-160 Mbyte range- any >>> opinions, recommendations? I understand that QUANTUM has on >>> disk cache. What affects have you seen with a disk with cache >>> built in? >> >>I can't comment on the cache, but Quantum makes a damn good drive, makes the >>Seagate look like the pig it is. It doesn't hurt to have it. Plus from >>ClubMac you can get a bare 100 meg Qunatun SCSI drive for under $350. Just >>gotta lie and tell them you got a "mac cx" or something like that. They >>think that an SCSI drive can't work in anything but Mac. >> > >I was able to try both a Quantum ProDrive 105s and a CDC Wren IV on my Adaptec >AHA1542B. I was SORELY disappointed with the Quantum. The seeks were slow. >Benchmarks for both seek and transfer rate were dismal at best, and worst of >all, the numbers were very erratic. At times I would get reasonable rates, at >other times the seek times were horrible. I also know that this drive doesn't >perform any better on a Sun workstation. About the best transfer rate I could >get was 500Kbytes/sec. My Wren IV does 1.3Mb/sec. Even an old Wren IIIHH did >better than the Quantum. It could get 800Kb/sec. Ross, did you try to reprogram the Quantum cache? I get 2.5MBytes/sec out of my 105s, but that is with the cache reprogrammed to work in the environment my drive works in. Is the cache enabled? I forgot, the Quantum drives for Apple have the cache disabled. Roy Neese Adaptec Senior SCSI Applications Engineer UUCP @ neese@adaptex uunet!cs.utexas.edu!utacfd!merch!adaptex!neese