Quick Raid Question

Ok I have 2 HD's
WD400JB 40gig 7200rpm w/ 8MB buffer
WD400BB 40gig 7200rpm w/ 2MB buffer

Can I run these in Raid 0, or will I have to just by another 400BB.
As far as I can tell I could run them together, just the JB would
run at the ran "speed" as the BB. Is that right?

Thanks

PS, almost forgot...anytime I have run raid, it has been onboard. This time I am using a PCI raid controller...how will I boot from the controller, will the BIOS auto-detect it and allow me to use it in the boot sequence??
Thanks again!

Codeman05 said:

Ok I have 2 HD's
WD400JB 40gig 7200rpm w/ 8MB buffer
WD400BB 40gig 7200rpm w/ 2MB buffer

Can I run these in Raid 0, or will I have to just by another 400BB.
As far as I can tell I could run them together, just the JB would
run at the ran "speed" as the BB. Is that right?

Thanks

PS, almost forgot...anytime I have run raid, it has been onboard. This time I am using a PCI raid controller...how will I boot from the controller, will the BIOS auto-detect it and allow me to use it in the boot sequence??
Thanks again!

Click to expand...

Yes you can use these drives in RAID 0. Like you guessed, the speed will be bottlenecked by the slowest drive, the 2Mb cache drive in this case.

The controller -if it's bootable, which they normally are- will be detected in the BIOS as a PCI or SCSI boot device. It shouldn't be a problem auto-finding the array and booting from it unless you have a drive on the default onboard IDE that is bootable too (in that case it would boot from that one first unless you specify otherwise in the BIOS).

ok thanks alot, would u think there would be much performance difference between 2 20gig 7200rpm drives and 2 40gig 7200 rpm drives...all running technically with 2mb cache?

Reason I ask is I also have a 20gig 7200 rpm drive and can get another rather cheap. When I benched the 40gig 8mb cache drive in sandra it gave me a score of 19k...granted the drive was 95% full...but that still seems crappy lol, I mean the 20gig is about 90% full and scored around 27k (although Sandra is prob just fubar)

Sandra has the most horrible disk bench on the planet. Don't waste your time using. If you must use something, try the disk bench in CLIBench, ATTO DiskBench (even though it sometimes lies too) or IOMETER from Intel, which happens to be the best (and hardest to use).

ok thanks for the info! Kinda figured those #'s had to be wrong.
Now for my 2nd question:
How much performance difference would I see between the following drives configed in Raid 0:
1xWD 40gig 7200 rpm 8mb
1xWD 40gig 7200 rpm 2mb
VS
2xWD 20gig 7200 rpm 2mb

I understand that the 40gig 8mb drive will be limited by the 2mb 40gig....BUT, how much slower would it run compared to the 20gigs???
Thanks!

Codeman05 said:

ok thanks for the info! Kinda figured those #'s had to be wrong.
Now for my 2nd question:
How much performance difference would I see between the following drives configed in Raid 0:
1xWD 40gig 7200 rpm 8mb
1xWD 40gig 7200 rpm 2mb
VS
2xWD 20gig 7200 rpm 2mb

I understand that the 40gig 8mb drive will be limited by the 2mb 40gig....BUT, how much slower would it run compared to the 20gigs???
Thanks!

Click to expand...

If the 20Gb and 40Gb disks are of the same type, just different size, then there will be virtually no performance difference. Disk size difference between models in the same series are determined by the number of platters- a variation that (hardly) affects performance.

ah ok that makes sense. I went ahead and decided to get another 40gig 8mb drive to run striping with