Hi, I've been playing a bit of Poker using the PKR application (It's a cider port from what I've seen). I'm finding that on my iMac (and not my MacBook Pro), after playing for a while the graphics go a little bit screwy then it freezes the entire system. To try and diagnose the problem I want to see if it's the app or the GPU which is causing the problem. Does anyone know how I can stress test the GPU? What's odd is that even though the app seems to be very CPU and GPU heavy, I don't really notice any fan noise from the iMac. I'm just concerned that it may be overheating. Any and all help very much appreciated.