I recently put in a 650 Watt power supply on my old Dell XPS that has a GeForce 8800 GTS video card (the 512mb version).? Is there anyway to actually get a rough estimate of what it uses as a wattage because I was told the 650 is too much for that but I was under the impression you need to have a lot of wattage or your computer won’t run or you will ruin your parts.? Any input to this?

I’ve always been an advocate for using the appropriate wattage for your PC.not that you need more, but you need less.? Most people “overbuy” on their power supplies and spend money on that component and short themselves on other parts in the PC.

The importance behind determining the amount of power needed for the computer is taking into account how much your processor demands.? The graphics card varies its power consumption as well but we’ll look at some charts on how much it usually uses on full load.

The GeForce line is a very stable and solid line except it actually uses more watts then the Radeon HD graphics cards.? You are right where the lack of power can hurt your PC (mainly you will experience a random sequence of reboots and power downs) but that’s mainly if you have under a 250W PSU with the graphics card you are running.? The only systems that need such large power supplies are ones that have quad-core processors with dual SLI video cards.

Using a guide made by Tomsharedware, we can look at the power consumtion of your grahics card to be:

GeForce 8800 GTS: 51.1 W?? 136.0 W? 11.3 A

The first number is for a 2D Desktop and the second represents what it would be in 3D on full load.? The last is how many currents (in amps) it uses simultaneously.

If you’re gaming, you can add on a bit more on that middle number to determine the amount of watts being used but as you can clearly see its no where near what most people thing.

If you further read up on that same guide, you can look at the amount of watts the processor uses and calculate how big/small of a PSU you truly need.

I recommend you really take a look at how much you really need as I think the 650W PSU you have right now seems to be a bit too much!