24amps on the 12volt line is low for a GTX. I would suggest upgrading to a
Quality PSU with minimum 30amps on the combined 12 volt rails. Corsair and PC Power and Cooling are two brand names that are highly recommended.
- GeForce 8800 GTX (Will be slightly overclocked)
- Intel Q6600 (Will be overclocked to 3GHz)
- ASUS P5N32-E Plus
- Zalman CNPS9700 NT CPU Cooler
- Plus some random fans inside the case
You're showing a single 24 amp +12v rail, it's not enough. The minimum psu reccomendation for an 8800 GTX equipped system as per EVGA is 26 amps, adding an overclocked Quad to the mix increases the load.
If you have no plans on going SLI a psu in the 30-35 amp range would do.
Here's a 450w\33amp model that would be fine http://www.buy.com/retail/product.asp?sku=205466485&Sea...
You cannot add the rails together to find max continuous amps. Each rail has a max amperage for that rail, however, total amps for all of the combined rails is actually less, 41 amps in this case. Look at this image, under 12 volts you have four rails with an 18 amp rating each, below that you will see the rating for all of the amps combined on the 12 volt rails, 41 amps