Thanks for all your help:
My virtual memory is already set to 50000 so thats not the issue.
I have ordered some molex powered risers to see if potentially thats the issue.
I have tried using a linux based OS but still get shit combined hashrates.
I am running the cards at stock settings so its not that
I am using a corsiar hx1200 powersupply, i have flicked it to single rail and will report the results. The other information is a bit confusing as i dont know how to manually assign things to specific rails in my psu.
I have tried some testing and it seems my rig just will not go above roughly 750 m/s if i plug 2 cards in, first one will hash at 450 and then next at 300, then if i plug all 4 in they will do some some random arrangement of hash rates to equal roughly 750. Has anyone ever heard of a problem like this?
Nic, did you ever get this sorted out? If not, let me know as I might have another trick or two you can try. Let me know if all of the cards show up in device manager, and if they all say working properly when you view the properties of each card.