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.
