Power Supply enough for SLI?
My power supple a Cooler Master Silent Pro 700W is on the list of usable PSU's for SLI. I run GeForce GTX 460 SLI and I never notice anything that would ever suggest that it isn't. However, I do not know much about PSU's so can anyone tell me if I would actually notice if it was an issue besides my computer shutting down to lack of power. Thank you.
Take a look at this: http://extreme.outervision.com/psucalculatorlite.jsp
Enter all of your computer specs as it requests and hit calculate. It will tell you if your PSU is adequate.
Also, how old is the PSU. If your close to the maximum power for the PSU it may fail because as a PSU age's, it can lose capacity. I prefer to add 20-25% capacity when I spec a PSU to be sure that I am using it well within its rated capacity.
For a system using two GeForce GTX 460 graphics cards in 2-way SLI mode NVIDIA specifies a minimum of a 620 Watt or greater power supply that has a combined +12 Volt continuous current rating of 37 Amps or greater and that has at least four 6-pin PCI Express supplementary power connectors.
Total Power Supply Wattage is NOT the crucial factor in determining power supply adequacy!!! Total Continuous Amperage Available on the +12V Rail(s) is the most important factor.
Overclocking of the CPU and/or GPU(s) will require an additional increase to the combined +12 Volt continuous current ratings, recommended above, to meet the increase in power required for the overclock.
The Cooler Master Silent Pro M Series M700 (RS-700-AMBA-D3), with its +12 Volt continuous current rating of 50 Amps and with two (6+2)-pin PCI Express supplementary power connectors, is electrically sufficient to power your system configuration with two GeForce GTX 460 in 2-way SLI mode.
The Cooler Master Silent Pro M700 has a weaker +12 Volt continuous current rating and only two PCI Express supplementary power connectors compared to a reputable name brand 700 Watt power supply that will have at least a +12 Volt continuous current rating of 58 Amps and four PCI Express supplementary power connectors.
One of my systems has an OC'd Q9550, 4 GB RAM, a GTX260 - a card with close to identical power requirements to a GTX460, a Gigabyte EP45-UD3P motherboard, 3 hard drives and an optical, and a Soundblaster card all powered by a Corsair 750TX.
Running 3 instances of Prime95 to load 3 cores of the CPU and 3DMark06 to load the fourth core and the GPU, it pulls 375 watts from the wall as measured by my Kill-a-Watt meter. Figuring 80% efficiency, the system pulls 300 watts from the PSU.
A second Gtx460 would pull another 150 watts or so for a total of around 450 watts. Although I would prefer a better power supply, your PSU is adequate in terms of overall power, 12 volt capacity, and total number of PCI power connectors.
Your first sign of inadequate power would probably seemingly random reset/reboot cycles during heavy (gaming) 3D loads.