[comp.periphs.scsi] SCSI and software cacheing

rspangle@jarthur.claremont.edu (The Duke of Dark Corners) (04/17/91)

In the recent discussion about average seek time, Mr. Neese mentioned that
the Adaptec 1542B (and presumably most other SCSI controllers) remaps the
sectors so that any disk appears to have 64 heads and 32 sectors/track.

Now my question is, how does this affect the performance of software disk
caches like HyperDisk, QC, and SMARTDRV?  They seem to want to read in an
entire track at a time.  But if the physical drive has, say 26 sectors per
track, or some other strange number (one that isn't 32), then it seems that
you would want to read ahead a smaller number of sectors, to avoid
unnecessarily changing tracks.

Are there any caches which work better with SCSI than those I mentioned?
What is the best way to set up the cache so it coexists nicely with SCSI?

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|   Randy Spangler                   |   Get your mind out of the gutter   |
|   rspangle@jarthur.claremont.edu   |   you're blocking my periscope      |
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