Help with SCSI RAID. HD Tach scores are too low.

[Jaimin]

Recently bought a 2100s Adaptec SCSI Raid card, and three WD Enterprise 10k u160 drives. I was pretty excited cause everything was easy to setup. It came with a linux boot cd which let me configure my RAID setup. I put one disk as a book disk, which I loaded win2k on too, and two other disks in a RAID-0 setup. After a little while of using my computer I decide to benchmark my hdd's cause I want to see if I am benefiting from the RAID. So I use sandra to benchmark and it gives me crazy low results that are way under the ata 66 7200rpm specs. I know sandra is not that reliable so I then try hd tach. I got the following results:

For the single u160 WD 10k drive:

Random Access Time: 8.9ms
Read Burst Speed: 49 mbps

Read Speed Max: 27815 kps
Read Speed Min: 12102 kps
Read Speed Average: 22950 kps


For the RAID-0 Partition (2 indentical drives which are the same as the one above)


Random Access Time: 9.1ms
Read Burst Speed: 21.9 mbps

Read Speed Max: 27886 kps
Read Speed Min: 18053 kps
Read Speed Average: 24572 kps


The access times seem too high and the read speeds are way to low. And all the RAID does is increase the average. These scores seem way off. Can anyone tell me what I can change, or are these scores what I should expect?

Thanks,

Jaimin

 

[Smbu]

It's probably your Adaptec raid card. Adaptec Raid cards are known to perform pretty badly(e.g. 2100, 3200, etc.). You can read more about it in the forums over at Storage Review.

 

[Jaimin]

But do you really think that the scsi card alone could cause my drives to perform lower than ide raid. I would understand if the adaptec performed underpar compared to another scsi raid card, but these numbers are too low.

 

[rommel]

thats slower then a single x15 cheetah