Thank you for your reply

Alright so I have switched up the ports so that my drives both run from the on board intel controller instead of marvel.
My mobo is a Asus P8Z68 V-Pro.
(Switched the ports from both in dark blue to both in grey - if you look at the mobo specs/pic).
I have enough ports to swap things around, still at 6gb/s.
The drives are a OCZ Sata 3 vertex and a WD Hard Drive.
I saw a similar thread on your forums suggesting this, post back with comments if I did something wrong in this case perhaps?
Thanks for your help!