Re: anecdotal ccd interleave performance numbers on sparc64

On Mon, Jul 24, 2006 at 12:33:56AM -0700, Erik E. Fair wrote:
> I'm setting up an UltraSPARC replacement for an older Sun SPARCstation 20
> running NetBSD. After a little advice from ICB, I tried some quick testing of
> different ccd interleave numbers for optimal raw read and write performance
> in ccd, striped across two 7200rpm SCSI disks, on two separate controllers.
> 
> The optimal interleave number for this configuration appears to be 64.

Sure, if you only care about a single stream of I/O.

Much better performance for most applications can be had by using a large
prime number as the interleave factor, which will let the disks work in
parallel for most pairs of requests.