Re: Areca 1260 Performance (was: File Systems - Mailing list pgsql-performance

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.