My 8800 GTX card has gone bang, and though it is going to be RMA'd in the mean time I needed a new Graphics Card. Unfortunately I want a little bit over the top, and ended up buying a Nvidia GTX 295 graphics card.
When my wife sees the money comig out of the joint account there is going to be trouble. However, I didn't notice at the time , but the reccomended power supply is a minimum 680 Watts, my existing power supply is a Enermax 650 modular SLI 2.2 compliant.
Can my exisiting PSU cope with the demands of a single 295, or is it best just to upgrade the PSU?
The rest of my system is a
2 x SATA 2 Hard drives
1 x DVD writer
3 x 120 MM fans
1 x GTX 295 graphics card - with added divorce option .
If a new PSU is required what are the reccomendations.
I don't know the exact numbers, but I believe the 295 has very low power requirements considering its performance. I'm not sure about the quality of your PSU but i'm fairly certain a high quality 650w psu would be enough for a single 295. I would think you would be ok if your PSU Is a high quality single rail model. However if it's not, this is an excellent upgrade option considering it's $/quality -
There's no general rule AFAIK. The PSU manufacturer is supposed to say how many amps are available when combined. It's usually less than the sum of all rails. For example if you see something like 18A+18A it's usually around 30A combined, not 36A. Antec is an exception, because in their case you can often just add them up like 18+18=36.