RAID 0 with Western Digital Disks

[sso]

I am in the process of building a new system for extremly Graphics and File intensive operation, and finding the best RAID setup for reliable data transfer.

In connection with this I have been working on debugging this system.

After intensive discussion with WD we have now concluded that one of my new WD2500JS SATA II drives must have surface damage on it. On the WD Diagnostics Extended Read and Write zero tests it performs 20% slower than the other identical drive, so I will send it back. Through this discussion with WD it became clear that the "desktop models" of their drives (which includes the WD2500JS in question) performed extended error correction work before responding to requests from the controller. When this happens in a RAID 0 array it ends up responding to the controller request to late, and thus the controller consideres the drive as having gone offline.

The suggested solution to this would be to use one of the Raid Edition drives (SD, YR series). However these are only SATA I series drives, and thus have a lower transfer rate. As so many times in life you cant have it all (yet)... The question is which is better:

a) 2 SATA II WD2500JS / WD2500KS drives which in case of surface errors may timeout, but during normal operation handles a transfer rate of 300 MB/s.
b) 2 SATA I WD2500SD Raid edition drives, with a limit on error correction before responding to the Controller but with a transfer rate of only 150 MB/s.

Its like taking out an insurrance policy - maybe you need it, and maybe you don't...

Both types have seek time of appx 8.9 ms, so no difference there.

Your advise would be appreciated.


Thanks!

 

[Superguy]

I wouldn't get hung up between the transfer speeds. Even my Raptors in RAID 0 can't saturate a SATA I channel, let alone a SATA II. The 300MB/sec is the maximum channel transfer rate, not the actual speed the data will actually transfer from the drive to the computer.

Hit storagereview.com and take a look at the particular drives you're looking at. I doubt you'd see much difference between them.

If you're really concerned about performance, though, get Raptors. They'll be faster than either of those drives.

I've ran the Raptors in RAID 0 for nearly two years on both Intel and more recently Nvidia SATA controllers. They work great.

 

[sso]

Thanks for pointing out the obvious to me.

Thank you also for pointing me to a great site. Loads of information there...

I now see that my chase of 150 MB/s (1.5 Gb/s) vs 300 MB/s (3 Gb/s) is rather irrelevant, when the best SCSI drive (Maxtor Atlas 15K II) only delivers a peak of 97.4 MB/s...

There is actually in the Specs from WD a clear indication that the SD and YR are slow compared to the JS and KS.

Cheers

Stephen