For a system using two AMD reference design Radeon HD 7950 (non-Boost Edition) graphics cards in 2-way CrossFire mode AMD specifies a minimum of a 750 Watt or greater system power supply. The power supply should also have a maximum combined +12 Volt continuous current rating of 45 Amps or greater and have at least four 6-pin PCI Express supplementary power connectors.
Total Power Supply Wattage is NOT the crucial factor in power supply selection!!! Sufficient Total Combined Continuous Power/Current Available on the +12V Rail(s) rated at 45°C - 50°C ambient temperature, is the most critical factor.
Overclocking of the CPU and/or GPU(s) may require an additional increase to the maximum combined +12 Volt continuous current ratings, recommended above, to meet the increase in power required for the overclock. The additional amount required will depend on the magnitude of the overclock being attempted.
Check out my guide for help on wattage requirements and PSU selection. Check out PCPartPicker for exact info on wattage. Just go to system build , add your selected parts and check the estimated wattage. Get a PSU 100-300W above your needs depending on your requirements and budget.
ATX12v PSU Guide
Last updated on 27th July 2013. Will be frequently updating this guide until I find it time to write a new one. Hello Buddies and Builders , This guide is to solve those "Will my PSU be enough ?" or "Need PSU Help ?" questions on the forum. Before... See full content