Originally Posted by Veloce

I did a quick guesstimate of some of the values and it came out at around 350w needed.

According to that card's specs, the minimum requirements are a 400w PSU.

Originally Posted by Digerati

The difference is the 500 watt will be working hard the whole time while the 800 watt supply will be loafing along.

Correct me if I'm wrong Bill but does this mean that more is better? Anyway PSUs aren't my specialty but you should factor in for a possible expansion or system upgrade so that you won't wind up in the same boat that you are in now. If you think that you might be wanting to use 2 cards for more power then you will need a PSU with more power and more PCI-e power cables. Also considering that some higher end cards require a 6+2 cable and maybe even 2 cables you would definitely want 2 or more cables and maybe even a 6+2 cable.

Correct me if I'm wrong Bill but does this mean that more is better?

No. Many folks are under the impression an 800 watt supply ALWAYS uses 800 watts, and that a 500 watt supply always uses 500 watts. My point was, the motherboard uses what it needs, regardless the capability of the PSU. So if you need 500 watts, it does not hurt to put an 800 watt supply in there.

Anyway PSUs aren't my specialty but you should factor in for a possible expansion or system upgrade so that you won't wind up in the same boat that you are in now.

Ummm, please read my canned text again - I said that.

Hey,

Since i'm building a new PC soon anyway (see my thread in hw to upgrade a PC) I think i'll go for a trusted, fairly large PSU, possibly 1000W, that way i'll have plenty of room for upgrades (if they are needed)

I better get saving, everything seems to need upgrading all at once in my life :P

You want a comfortable headroom but there is no advantage to overkill. That's why I said to think ahead 2 or 3 years, and adjust for aging. If you calculate today for 6Gb of RAM and a 2nd graphics card, then it is not likely you will be "adding" anything more significant, in terms of power consumption, than a couple hard drives - so figure in 4 or 5 drives now if you want. Anything bigger than that you attach to your computer will likely come with its own supply.

Graphics cards are the big consumers in today's PCs. The better the graphics solution the more tasks the CPU can "hand-off" to the graphics processing unit (GPU) for crunching. And it takes little CPU horsepower to hand off tasks across a wide bus to another processor. This is why the latest GPUs have more, WAY more transistors. The new Intel Core i7 CPU, for example, has 731 million transistors on die, which includes large chunks of on-die cache while Nvidia's GT200 GPU comes with 1.4 billion transistors, and no on-die cache.

Still, AMD and Nvidia are working to hard to make more powerful graphics engines that consume less (or at least no more) power than todays. So if you factor in two powerful cards from today in the calculator, "replacing" those cards 3 years down the road with more efficient cards will not increase power demands significantly.

I see no problem adding an extra 15-20% for good measure, but if you only need 500, a 1000 is overkill.

I see what you mean.

I really need to just sit down and figure out what's going in this new PC, as so far i only have an idea of the motherboard, CPU and GPU.

Thanks for the help so far guys.

Thats a really good start and thats actually the biggest parts. Now do you have specific models in mind or do you know just what kind of processor that you want? What you need to do is to say that I want this CPU and then you go to a website that sells computer parts (I prefer newegg) and search for only the motherboards that support the CPU that you want. Actually when you decide on a CPU before you "set that in stone" by buying a motherboard you might want to check out the prices and see if they are acceptable. For example you might consider Intel's i7 only to discover how much more expensive they are than the core 2 line and then change your mind. You need to think about what you do most with your computer that will test its limits and buy the appropriate processor & GPU. Once you decide on MB, GPU, & CPU that only leaves mainly RAM, cooling system, PSU, hard drive(s), and optical drive(s).