Originally Posted by the_beast
Make your mind up! If you're going onboard, you're not using hardware RAID. You're using host-based RAID, or fakeRAID - basic hardware primarily controlled by drivers to do the RAID processing. But it's pretty much irrelevant - what I posted applies to hardware RAID also.
FakeRAID controllers in my experience are crap with small writes that are smaller than a full stripe width - to mitigate the issue you force the controller to write a full stripe at once. To do this set your block size to be equal to the full stripe width. With 2 active disks (3 drive RAID5 = 2 active drives) it works out nicely - set your stripe size to 32K (when you build the array in your controller) and your block size (when you format the partition) to 64K (the max under NTFS).
For any RAID array you should ensure your partitions are aligned. If you're using Win7 you shouldn't need to worry, but it pays to check. You just add in an offset when you partition your drive - for further details you can search for alignment (many of the links you'll get are for SSDs - but the methods are the same).
I'm sorry but i don't know where you get your information, please don't confuse people with misinformation and over-complication
An onboard controller is indeed a hardware controller and is not processed through the Operating System. While the OS does indeed provide drivers, the actual computation is done through the BIOS. Drivers are nothing more than updates to the code needed to create an array. Software RAID is something completely different and was never brought up in this discussion.
The max stripe size is well over 64kb for NTFS(something close to 1024kb).
Furthermore mis-alignment of RAID arrays only become an issue in large arrays where all data needs to be written synchronously and the drives need to be aligned to offset the partition. Yes you may argue there will be a mis-alignment nonetheless, but it is insignificant.
Lastly(@Xeb), just remember that the smaller you make your stripe size, the more CPU intensive it shall be. For general use, a 64kb-128kb size is recommended. For larger files you go up to 1mb, and for smaller you go down accordingly.Edited by Razultull - 4/18/11 at 10:36am