RAID 0 performance less than IDE single drive!

[bobross]

I have two SCSI-2 7200 RPM drives configured as Raid 0. In Sandra they score 34,894. I then tested my single 7200 rpm IDE 133 drive and it scored 49,976. How is this happening?

[larva]

Sandra is essentially useless for serious performance evaluation, especially when it comes to hard drives.

[sramjones]

Originally posted by larva
Sandra is essentially useless for serious performance evaluation, especially when it comes to hard drives.




^^^^^^^^^^^^^^^^^^^^^^^^^^^^

[wquiles]

Try using the ATTO Benchmark Utility(Bench32) utility to compare drive performance as it is supposed to be more accurate/realistic. Here is a screen shoot of the software:
http://www.quickbench.mynetcologne.de/B_Attodiskbench.htm

[bobross]

Thank you wquiles. This is looking much better, but my write totally sucks. Using two barracuda 7200 rpm SCSI drives. Arghh!!

http://www.freewebs.com/tosell/craigslist/diskbench.JPG

[tom10167]

Don't you notice a realistic speed difference?

[RangerJoe]

SCSI drives do not really see that much of a performance gain until you get 10,000-15,000 rpm drives. the seek times on 7.2k drives just is not much better than IDE, and write is taken down because of having to go through the card and all that before writing to the drive.
That is not the main reason, but the gains just are not that great. seek times, and buffer of slower scsi drives are no better than most moden IDE drives

If you want to see real gains with scsi, buy two 10k drives with 4-5 second seem times. that is the way to get the speed you are looking for.

[bobross]

tom10167: Seems slow to install and load, no gains. :(

Thanks for the replies. I do have three atlas 10k U160 drives around here somewhere. I’ll try those, and post some results :)

[XWRed1]

You don't have both drives on the same ide channel, do you? That would destroy striped performance.

[Mico]

Yeah...make sure they aren't on the same ribbon cable...that would definitely cause a slow down...a rather large slowdown.

[donny_paycheck]

Change the total length to 32mb and the queue depth to 10. Small sizes get hung up in the on-drive cache and can skew results. I wasn't aware of this myself until just recently, but changing it made my scores much more consistent, as well as improving them.

Welcome to the forums.

[bobross]

XWRed1, Mico. I am using SCSI. One cable can handle 15 drives no problem.

donny_paycheck, I'll try that and post results...

[shadowdr]

Raid 0. can also suffer greatly if there is an ide drive that does not have a page file present.Try spliting your page file between the raid and the ide.