On Thu, Apr 21, 2005 at 10:44:23AM -0500, Drew Winstel wrote:
> It has been a busy week, I know, but does anyone have any tips?

You could try setting read cache disable, I don't know if that setting
must be honored, or how ATA/SATA handle it. See mode page 8 for SCSI block
commands. 

The sg utilities sg_modes can probably set it.

Better yet, do IO to more locations on the disk, not just the very
beginning and the very end.

> The reads we're calling are getting cached.  If we call 100 reads--50 to the 
> beginning of the drive alternating with 50 to the end--the first read will 
> sometimes appear to have a realistic result, then the rest will all complete 
> in the neighborhood of 10 microseconds.  

-- Patrick Mansfield
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