davis@clocs.cs.unc.edu (Mark Davis) (06/12/89)
SUMMARY: 8 bit ST01 SCSI controllers do pretty well. In article <8356@thorin.cs.unc.edu> I (Mark Davis) wrote: > >What is the performance of 8 bit SCSI controllers running SCSI hard >disks in real systems? > >This question came up because of the large number of Seagate "matched >pairs" on the market. My favorite right now is the ST296N 80 meg >drive with ST01 SCSI host adapter. At mail order prices of under >$600, this is a pretty good deal considering you get the controller >too. Here is the data so far. More data would be nice, but this should be sufficient to answer the question of how much a hit you take by using an 8 bit SCSI controller like the ST01 instead of the more expensive 16 bit controllers: Tran Bus Disk Disk CPU Rate Mhz Control Type Tran Speed Test Reporter ==== === ======= ==== ==== ====== ==== ======== 850K 12 ST01M Priam 738 10Mb 286/12 Core ojala@spica.hut.fi 800K 8 ST01M Priam 738 10Mb 386/16 Core ojala@spica.hut.fi 1.2M - Adaptec Maxtor 650M 15Mb 386/16 - ojala@spica.hut.fi 1M - WD7000ASC CDCWRENIV 300 15Mb 386/16 - keithe@tekgvs.labs.tek.com 820K - WD7000ACS CDCWREN 150 10Mb 286/10 - keithe@tekgvs.labs.tek.com 800K 10 PS2ESDI/A IBM 70Meg 10Mb 386/20 Core Coretest 2.81 Notes: 1. When ranges were given, I took the lower number. 2. WD7000ACS and Adaptec are 16 bit controllers. 3. ST01M is a ST01 with a third party BIOS ROM. 4. I could not accurary identify the transfer rate of the CDC 150 Meg drive, but assumed that it is a 10 Mbit/sec drive. My assessment is that the ST01 can do as well as the 16 bit controllers as long as it handles 10 Mbit/sec disks. This seems to be more a result of the 10Mbit/sec limit than for the 8 bit bus interface. What I really need is data on a 10 Meg/sec drive with a 16 bit controller. Since I was not sure about the CDC WREN 150 Meg drive, I added the PS2 ESDI controller/drive combination. This data seems to confirm that 800K is about the best transfer rate you will see with a 10 Mbits/sec disk. I should also add that if you are running DOS, this is great. The ST01's performance is quite adequate. On the other hand, if you are running a multitasking operating system, then other factors may make 16 bit controllers better. [But I live in a DOS world ...] [Well, not really, but when it comes to PC's, I do.] Thanks for all the help - Mark (davis@cs.unc.edu or uunet!mcnc!davis)