here is a link that discusses RAID3 and RAID5

http://www.bytepile.com/RAID_3_vs_RAID_5_In_HPC.php

Since the introduction of 8 stripe parity across all disk types on CLARiiON for Raid 5, bandwidth is comparable to that achieved with Raid 3.

The data path is shorter for Raid 3 thus a very marginal performance gain can be achieved.

That said, as per the other reply reference, the conclusion is such that unless you have specific single thread large block sequential as an exclusive access profile per disk group (and they rarely are), the recomendation would be to go with Raid 5.

I expect this to be true for newer Flare codes an newly created Raid Groups.
I'd say if you come from Flare 19 and you created a RG in Flare 19, that upgrading to Flare 26 doesn't improve data throughput at all, since the layout of the parity isn't suddenly changed. Am I right here ?