pgsql-hackers@postgresql.org

On Sun, Jun 22, 2003 at 09:01:35PM -0700, Sean Chittenden wrote:
> As things stand, because O_DIRECT is an execution fast path through
> the vfs subsystem, I expect the speed difference to be greater on
> faster HDDs with high RPMs than on slower IDE machines at only
> 5400RPM... thus trivializing any benchmark I'll do on my laptop.  And
> actually, if the app can't keep up with the disk, I bet the fs cache
> case will be faster.  If the read()'s are able to keep up at the rate
> of the HDD, however, this could be a big win in the speed dept, but if
> things lag for an instant, the platter will have to make another
> rotation before the call comes back to the userland.
If it would help, I have a quad xeon-550 with a 4 drive raid5 and 2
drive mirror (all SCSI, 7200RPM I think) available.
-- 
Jim C. Nasby (aka Decibel!)                    jim@nasby.net
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