Suggest some real-world RAID benches

[Jimbo Mahoney]

Hey guys,

I'm buying another 36GB Raptor to have a play with RAID-0. I'll be using the drives as my OS and programs (not games though) drive and testing various stripe and cluster sizes.

My concern with other people's use of RAID 0 is that they set the stripe size too big to really benefit their system (ie 64kB when >90% of their files are <64kB) because they don't understand striping and/or go on what HDTach tells them (we all know HDTach likes big stripes ).

Can anyone think of any real-world benchmarks I could run? Windows boot time is one obviously...

My theory is that my stripe size should be ~ (median file size on the drive/the stripe width) (ie 2 for two drives in RAID 0) and that the cluster size should be ~ (stripe size/2).

I expect when I set the cluster size too small, CPU usage and / or access time will become an issue, offsetting the increased throughput.

And before anyone jumps on the old 'RAID 0 doubles your chances of data loss' - it's cool, because it will be on my gaming rig and I use Ghost images for my OS. If the RAID volume gets screwed for whatever reason, it's no biggie.

 

[Jimbo Mahoney]

I don't have any information but also wanted to know.

My understanding regarding stripe size is that if you use it for Windows a smaller stripe size (<64k) is better but if you also have games and storage a larger one might be better (64k/128k)

Using JDiskReport to give file size distribution for each drive, the file sizes don't seem very different from the C: (Windows) drive and the E:\ (Games) drive on my system.

 

[Jimbo Mahoney]

Looking at my C:\, I'm leaning towards an 8kB stripe.

46% of my files are larger than 16kB, so they will all get striped.

If I set the stripe to 16kB, only ~ 30% of my files would benefit from the stripe (ie those over 32kB).

I'll let you know how it goes.

 

[Jimbo Mahoney]

Somehow you need to factor in the frequency at which they're accessed. A lot of files on your C: drive just sit there or are only accessed once at boot, others are accessed more often.

That'll be easy to do then....