Re: scsi vs ide performance on fsync's

Mark Hahn (hahn@coffee.psychology.mcmaster.ca)
Tue, 6 Mar 2001 18:27:21 -0500 (EST)


> itself is a bad thing, particularly given the amount of CPU overhead that
> IDE drives demand while attached to the controller (orders of magnitude
> higher than a good SCSI controller) - the more overhead we can hand off to

I know this is just a troll by a scsi-believer, but I'm biting anyway.

on current machines and disks, ide costs a few % CPU, depending on
which CPU, disk, kernel, the sustained bandwidth, etc. I've measured
this using the now-trendy method of noticing how much the IO costs
a separate, CPU-bound benchmark: load = 1 - (unloadedPerf / loadedPerf).
my cheesy duron/600 desktop typically shows ~2% actual cost when running
bonnie's block IO tests.

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