My brother has a motherboard with several PCI-E x1 slots. He currently has a 4850 hooked up that he uses exclusively. If I hook up one or more GPUs on the same board and use them at full load with Bitcoin, will it affect his video performance on his 4850 in any way? This is assuming I can pick and choose what video devices I want Bitcoin to generate on. Can I?
In addition, will a quality 500W dual-rail OCZ power supply be able to support a dual-core CPU (E8200), a 4850 and a 5770?
To my understanding, most manufacturers underrate their power supplies and overrate the wattage requirement of their GPUs. Your mileage may vary.