I appreciate your suggestions, Ron. And that helps answer my question
on processor selection for our next box; I wasn't sure if the lower
MHz speed of the Kentsfield compared to the Woodcrest but with double
the cores would be better for us overall or not.
On 6-Dec-06, at 4:25 PM, Ron wrote:
The 1100 series is PCI-X based. The 1200 series is PCI-E x8
based. Apples and oranges.
I still think Luke Lonergan or Josh Berkus may have some
interesting ideas regarding possible OS and SW optimizations.
WD1500ADFDs are each good for ~90MBps read and ~60MBps write ASTR.
That means your 16 HD RAID 10 should be sequentially transferring
~720MBps read and ~480MBps write.
Clearly more HDs will be required to allow a ARC-12xx to attain its
peak performance.
One thing that occurs to me with your present HW is that your CPU
utilization numbers are relatively high.
Since 5160s are clocked about as high as is available, that leaves
trying CPUs with more cores and trying more CPUs.
You've got basically got 4 HW threads at the moment. If you can,
evaluate CPUs and mainboards that allow for 8 or 16 HW threads.
Intel-wise, that's the new Kentfields. AMD-wise, you have lot's of
4S mainboard options, but the AMD 4C CPUs won't be available until
sometime late in 2007.
I've got other ideas, but this list is not the appropriate venue
for the level of detail required.
Ron Peacetree
At 05:30 PM 12/6/2006, Brian Wipf wrote:
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.
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