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From: jt34@prism.gatech.EDU (THOMPSON,JOHN C)
Newsgroups: comp.periphs.scsi
Subject: Re: Controller Cache vs. Software Cache
Message-ID: <31288@hydra.gatech.EDU>
Date: 13 Jun 91 13:37:12 GMT
References: <30738@hydra.gatech.EDU> <633@zds-ux.UUCP>
Distribution: comp.periphs.scsi
Organization: Georgia Institute of Technology
Lines: 14

You mention several intersting points with regards to drive arrays. In order to
take full advantage of a dirve array you need to have the array working on
multiple requests simultaneously. Scsi 2 allows for command queing and
overlapped commands, just the kind of thing necessary to maximize performance 
from a disk array. The problem as I see it is that most OS device drivers do
not yet support SCSI 2 and hence would limit the potential effectiveness of
an array. Rather than change all the device drivers for all OS's might it
be easier to implement these features with a smart caching host adaptor?

-- 
THOMPSON,JOHN C
Georgia Institute of Technology, Atlanta Georgia, 30332
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