A good multi GPU custom PC works only as well as the power supply unit that powers it and one of the best solutions for this are Cougar Modular Power Supplies. These power supplies guarantee steady power to all components, especially power hungry graphic cards, which they do by the combination of a high quality Japanese capacitors and modules connected to the transformers to ensure stepping down the current for respective components falls within less than 3% of natural fluctuation. Placing high loads on these supplies is not a problem, heat is removed via the Hydro Dynamic Bearing fan, which is effective at removing heat from the PSU and CPU and is quiet to boot.
