Sign in with
Sign up | Sign in
Your question

RAID 0 slower than single drive!?!?!

Last response: in Storage
Share
January 11, 2003 1:59:04 PM

I hope somebody can help me figure out what's happening here. I have a 30GB and a 40GB WD Hard Drive which I just set up as a RAID 0 stripeset on a Gigabyte GA-7VAXP board (Promise 20276 controller). This is my first forray into RAID so I may simply be confused as to what is supposed to happen. I got the 60GB "logical" drive I was expecting, and it seemed to be perhaps a bit faster once I got win2k (NTFS) loaded up (drivers gave me headaches for awhile...anyone having trouble with this don't bother with the drivers that came with the mobo...get new ones from gigabyte's website). It wasn't quite the screaming storage system I was overly-optimistically hoping for but I wanted to see the numbers.

I ran SiSoft Sandra 2003's HD benchmarker before installing the RAID setup when I just had the 30Gigger set up as a normal drive. When I ran it again on the stripeset I found that the Sequential Read and Sequential Write speeds had more or less doubled which pleased me immensely!

Then I noticed that all the other tests had dropped significantly, including Buffered Read/Write, Random Read/Write, and Avg Access Time (the latter of which I understand). I don't have the numbers with me right now but I could throw them up after work if anyone wants to see the specifics. My concern is whether all these numbers are supposed to be dropping or if I may be doing something wrong somewhere. I understand the concepts behind each type of read/write but I don't really know when they are going to be applied in practice or how each particular one affects overall performance. I'm also not 100% sure that Sandra's tests would be accurate on a raid array. Any insight, advice, or sharing of experience would be greatly appreciated.


Hardware: the parts of a computer that can be kicked.<P ID="edit"><FONT SIZE=-1><EM>Edited by mongre on 01/11/03 03:12 PM.</EM></FONT></P>
a b G Storage
January 12, 2003 2:36:37 AM

I had this same question last fall. HD Tach was giving me some very low numbers. Someone on this forum said to get WinBench 99 from Ziff Davis. Try it. If you don't get better #'s there, you've got hardware or setup problems.
-Brett
January 12, 2003 3:57:23 AM

Its more a benchmark program problem than anything else. Sandra isnt very good with raid arrays, nor many other benchmarksing programs.

Also, what stripe size did you pick? That influences performance too.

<b><i>The Very Hungry Caterpillar</i> - George W. Bush's favorite childhood book.
Note: This book was first published a year after Mr Bush graduated from College.</b>
!