I might recommend looking at my post earlier in this thread
, as I list a table of SQLIO result from actual systems in a variety of RAID setups, both spindle and SSD disks, over different IO sizes and IO queue depths.
If you want to know the difference between RAIDx and RAIDy on your particular setup, I would very much recommend running an exhaustive SQLIO set over the metrics appropriate to your workload; it's not unknown to see a particular setup have one or another odd quirk for a specific data transfer type at a given RAID level (and/or stripe size); keep your firmware, drivers, SAN controllers, etc. updated.
In some older hardware, I sometimes saw a cap on writes that was very unexpected to me.