XP256, Raid-1 vs. Raid-5 performance

[Dave Wherry_1]

Has anyone using the XP256 benched the performance differences between Raid-1
and Raid-5?
We're using the 36.9GB drives. A Raid-1 array gives about 64GB usable space
and a Raid-5 array about 102GB. We initially put all of our production data on
Raid-1 for what we were told is the faster performance. I'm hearing that on
the XP Raid-5 is almost as good if not equal to Raid-1. Has anyone actually
seen this?
I'm considering moving to all Raid-5 to get the higher usable space from my
arrays and split the load between my 2 ACPs.
Comments please.

P.S. This thread has been moevd from Disk Array to Storage Area Networks (SAN) (Enterprise). - Hp Forum Moderator

[Mark W.A. Hinkle]

My old boss, Ken Wood, of Hitachi Data Systems co-wrote a performance paper with someone from Oracle on this very topic. Depending on the blocksize(s) in question, it is possible for RAID 5 to outperform RAID 1. As you may know, the XP-256 is essentially the same box as Hitachi's 7700E.

You may contact Ken Wood via email: ken.wood@hds.com for more details.

FYI..............Mark Hinkle

[Dave Wherry]

Mark,
Thanks very much. Ken emailed the white paper to me and it is exactly what I was looking for.
Their tests showed Raid-5 to perform better than Raid-1 in this Oracle test.
It should put our concerns to rest and gain me about 160GB of space.