Raid performance...

Right I've been pondering this for a while now, I realize it might be beating a dead horse asking this again but I can't find a satisfactory answer any ware.

I'm about to rebuild my workstation, and I will be using a rather large Raid-5 for data storage, so I will already have a HW raid controller.

Was thinking of using 4 disks for my OS/Game volume, but I can't decide if I want to use them in Raid-5 or Raid-0+1. I just can't figger out if what would give the best performance and still have redundancy. Disk is cheap so I don't mind "wasting" 50% for redundancy, but I want to maximize my Game & OS I/O on those 4 disks as good as possible.

Anyone have any concrete data from trying this out, what would give the best performance of the two? and no I'm not interested in going SSD yet, in a few years maybe.

Cheers!