Nvidia Geforce 8800 GTS 640MB vs 512MB

I was looking for another xfx geforce 8800 gts 640MB card for SLI when I checked the charts and noticed that the 512MB version performed better in the charts I looked at. I can't read a lot out of them, and when I chose the card a couple of years back I mostly looked for a popular and stable card. But I don't see a difference between the card except for higher memory, and I would expect that was a good thing.

Could someone explain?

They use a different processor. The 512mb card is much faster.

BTW as they use a different processor you cannot use one in SLI with your current card. You would most likely be better off just buying a new single card than SLIing you 8800GTS 640mb.

What is you monitor's native resolution? Also what processor and power supply are you using?

Something like this would be quite good for your resolution;
http://www.newegg.com/Product/Prod [...] 6814102873
It is approximately twice as fast as your current card, DX11 and actually uses significantly less power, especially at idle.
Your processor is getting a lil weak these days but actually is still decent if you can overclock it. On just the stock cooler you should be able to get it up to 3.3-3.5ghz and then it is fine.

Well keep in mind that's just the best deal I'm seeing at the moment. When you are actually ready to buy something come back and ask again because the best choice may be different by then.

It's cheaper. You'll gain no advantage from using an XFX card even if the motherboard is made by them.