Different views

[rangi]

I'm currently running a RAID0 stripe set at 32bit would there be any advantage going to 16bit in my next array? My friends and I have differing views on if there is any advantage at all. Today I'm picking up 2xWD2500KS caviar 16mb cache HDD's, I would like to RAID0 this pair has anybody got any opinions on this?

 

[Snugglebear]

Do you mean 32KB (kilobyte) vs. 16KB stripe sizes?

 

[rangi]

Do you mean 32KB (kilobyte) vs. 16KB stripe sizes?

Yes.

I use 32KB block size, seems to be default. I was curious if using 16KB or even 64KB block sizes would have an effect upon performance.

 

[stunt]

Heres a thread on the differances between the stripe sizes.
http://www.ocforums.com/showthread.php?t=310250

 

[I.M.O.G.]

In reference to speed, there isn't a lot to be gained.

However the larger the stripe size, the lower the overhead relative to data (larger chunks of data, fewer chunks of meta-data). The metadata is information about the structure of the drive, not actual user/program data on the disk. Visually, heres an example:

Small stripe size (dashes are data, asterisks are metadata):

---*---*---*---

Large stripe size:
-------*-------

Now, you need to look at the size of the files on the drive. If you have a lot of small files, (files smaller than the stripe size) you are going to have a lot of slack space - space within a stripe that isn't utilized and goes to waste. However, if you've got a lot of large files, your going to come out ahead.