blgardne@esunix.UUCP (Blaine Gardner) (07/03/90)
My A3000 should be here within a few days, and I'm thinking about
upgrading it to a synchronous SCSI drive since the A3000 controller
supports synchronous SCSI.
A few questions:
1) What drives are known to work? If I understand correctly, the
"smaller" Quantum drives (40, 80, and 105 meg) do not support synchronous
mode, but the larger ones (120, 170, and 210 meg) do. Is this correct?
Are there other 3.5" synchronous SCSI drives worth looking at?
2) What kind of transfer rate can I expect with a synchronous drive?
Over 1M/sec, close to 2M/sec?
3) Has anyone actually done this? What do you think of it? Is it worth
it?
If you'll e-mail me your answers, I'll post a complete summary of the
responses.
--
Blaine Gardner @ Evans & Sutherland 580 Arapeen Drive, SLC, Utah 84108
blgardne@esunix.UUCP
{decwrl, utah-cs}!esunix!blgardne
DoD #0046 The Borg killed Laura Palmer!steveb@cbmvax.commodore.com (Steve Beats) (07/24/90)
In article <2036@esunix.UUCP> blgardne@esunix.UUCP (Blaine Gardner) writes: >My A3000 should be here within a few days, and I'm thinking about >upgrading it to a synchronous SCSI drive since the A3000 controller >supports synchronous SCSI. > >A few questions: > >1) What drives are known to work? If I understand correctly, the >"smaller" Quantum drives (40, 80, and 105 meg) do not support synchronous >mode, but the larger ones (120, 170, and 210 meg) do. Is this correct? >Are there other 3.5" synchronous SCSI drives worth looking at? Quantums and CDC Wren x drives work well in Synchronous mode, as do the larger Micropolis drives. I haven`t tried any others. BTW. All Quantum drives support Synchronous mode. >2) What kind of transfer rate can I expect with a synchronous drive? >Over 1M/sec, close to 2M/sec? > >3) Has anyone actually done this? What do you think of it? Is it worth >it? To answer both questions: No, for a single drive you will not notice ANY significant speedup. The bits are not going to come off the platter at more than 1.25 Mb/s! In the single drive situation you will gain a little system performance because the DMA chip will not hog the bus for so long when it bursts blocks of data to/from RAM. The only time sync xfer gains you anything is if you are using more than one drive simultaneously, in this case, the total bandwidth of all drives added together can approach 4Mb/s though individual drives will not exceed 1.25Mb/s. Steve