On 6-Dec-06, at 2:47 PM, Brian Wipf wrote:
Hmmm. Something is not right. With a 16 HD RAID 10 based on 10K
rpm HDs, you should be seeing higher absolute performance numbers.
Find out what HW the Areca guys and Tweakers guys used to test the
1280s.
At LW2006, Areca was demonstrating all-in-cache reads and writes
of ~1600MBps and ~1300MBps respectively along with RAID 0
Sustained Rates of ~900MBps read, and ~850MBps write.
Luke, I know you've managed to get higher IO rates than this with
this class of HW. Is there a OS or SW config issue Brian should
closely investigate?
I wrote 1280 by a mistake. It's actually a 1260. Sorry about that.
The IOP341 class of cards weren't available when we ordered the
parts for the box, so we had to go with the 1260. The box(es) we
build next month will either have the 1261ML or 1280 depending on
whether we go 16 or 24 disk.
I noticed Bucky got almost 800 random seeks per second on her 6
disk 10000 RPM SAS drive Dell PowerEdge 2950. The random seek
performance of this box disappointed me the most. Even running 2
concurrent bonnies, the random seek performance only increased from
644 seeks/sec to 813 seeks/sec. Maybe there is some setting I'm
missing? This card looked pretty impressive on tweakers.net.
Areca has some performance numbers in a downloadable PDF for the
Areca ARC-1120, which is in the same class as the ARC-1260, except
with 8 ports. With all 8 drives in a RAID 0 the card gets the
following performance numbers:
Card single thread write 20 thread write single
thread read 20 thread read
ARC-1120 321.26 MB/s 404.76 MB/s 412.55 MB/
s 672.45 MB/s
My numbers for sequential i/o for the ARC-1260 in a 16 disk RAID 10
are slightly better than the ARC-1120 in an 8 disk RAID 0 for a
single thread. I guess this means my numbers are reasonable.
