An important tip from one of our users: don't just check total power output, find out what you need in the way of current on each power rail. If you need 20 A on your +12V rails and the supply only has 15A, it doesn't matter how many watts the supply puts out: don't buy it. Make certain that you have ENOUGH rails, too: sometimes, you need more than just two +12V rails for your setup.
Replacing an existing power supply is easier: just get a replacement that meets or exceeds the specifications of the old one. (You can usually find those printed on the side of the supply.)
That said, here's a power supply that is compatible with most ATX format motherboards, puts out 680 watts of power (see specifications for exact distribution). Could this be your next power supply?
ATX12V and EPS12V CompatibleCompatible with the ATX12V and EPS12V standards, the APEVIA ICEBERG ATX-IB680W-BL power supply provides maximum stable power to feed the latest Intel and AMD processors as well as other components for desktop and entry-level server computer systems.
680W Maximum PowerThe APEVIA ICEBERG ATX-IB680W-BL provides a maximum power of 680W to deliver safe, reliable output for high-end computer systems.
Efficient CoolingTwo 80mm fans with crystal LEDs provide highly efficient cooling for the power supply and the whole system while delivers eye-catching fun.
Fan Speed ControllerAn integrated adjustable fan speed controller allows manual fan speed adjustments for the optimal balance between cooling performance and noise.
UV Reactive Cable SleevingsThe APEVIA ICEBERG ATX-IB680W-BL is equipped with cables that are wrapped in UV reactive sleevings, eliminating wire clutter for optimized air flow in the case.
1 x Main Connector (20+4 pin) 1 x 12V P4 / P8 (4/8 pin) 8 x Peripheral 4 x SATA 2 x Floppy 2 x PCI Express
High-tech aluminum casting with fire-resistant acrylic cover LED light switch - Fan LED lights can be switched to blue, green or red Multi-color coated components & PC board Excellent Ventilation Design: 2 x 80 mm crystal LED fans User-adjustable fan speed controller optimizing balance between noise reduction and necessary cooling Cable Management: all cables are sleeved to avoid clutter and to improve airflow UV Sensitive On/Off Power Switch, Power Plug and connectors Short circuit / over voltage / over current protection