Was using a 650w power supply in my computer and it is being replaced under warranty by the manufacturer due to it not working properly with a 850w power supply. Thing is that my PC only uses at most 500w. Currently using a 550w 80+ gold PSU which is plenty. So thinking 850w will be overkill for my system. Just wonder what the effects are of using a power supply in a computer rated much higher than needed and will ever used?