On a high end RAID controller, RAID 10 is, generally speaking, the highest performing RAID level. The high end controller uses all 4 disks (or 6, 8 etc) to satisfy read requests; while writes only ever require 2 disk accesses (writes to each part of whichever mirror is affected). High-performance mail servers, database servers, virtualisation servers and rendering servers all use RAID 10 to help ensure that disk performance is as high as possible.
With a four disk RAID 10 array, ATTO shows us:
Well, those results seem to be roughly in line with the 2 disk RAID 0 set for both read and write. Not too bad a result but watching the LEDs confirms that the RAID controller really does use only 1 disk in each mirror for read requests, severely limiting its performance (specifically disks 0 and 2 are used). Let’s see what HDTach has to say about the 4 disk RAID 10 set:
Again the performance is in line with the 2 disk RAID 0 set, which is to be expected. HDTunePro shows the now familiar performance arch rather than the perpetually decreasing curve; it's consistent, if not expected:
Well no drama here, performance is nigh on identical to the 2 disk RAID 0 set. The random IO profile is similar:
