Re: [TCLUG:12134] SCSI vs. IDE

["Eric M. Hopper" <hopper@omnifarious.mn.org>]

On Tue, Jan 11, 2000 at 04:30:09PM -0600, Chris McKinley wrote:
> 
> The disk transfer rate is limited not by the interface, but by the
> spindle speed.  The bus transfer rate then dictates the number of
> drives you can have before you get I/O contention.  IDE, even ATA66,
> can only fill the bus for the size of the drive buffers, whereas a
> properly striped RAID setup can keep sustained data flows.  Other
> advantages are that SCSI supports up to 15 devices / channel, SCSI
> supports other devices than storage, and SCSI uses less than half the
> CPU resources of IDE.

	Hard data, yes!  :-)

	OK, suppose you hook up 4 hard-drives to your IDE interface and
use software raid to stripe aross them?

	Your comment about CPU indicates that SCSI is better for even
one drive.  This mirrors an experience I had when I was running a heavy
test that read and wrote random 8 meg segments of a 64 meg file.  My
machine slowed down to a crawl and all the CPU time was being spent on
'system'.

	Why does IDE use more CPU?

Thanks,
-- 
Its name is Public Opinion.  It is held in reverence. It settles everything.
Some think it is the voice of God.  Loyalty to petrified opinion never yet
broke a chain or freed a human soul.     ---Mark Twain
-- Eric Hopper (hopper@omnifarious.mn.org  http://omnifarious.mn.org/~hopper) --

PGP signature