I am a little vague on the intended use of the 4th ram slot on the new i7 boards. But as algol said bump your ram up to 6gb +. The ram is the limiting factor in your hardware configuration.

As for how much power a card is using, the mfg's usually list the max power consumed (in amps) somewhere on thier websites. Check the user forums for your cards mfg. For example the 8800gt used ~ 30 amps at full power. I would expect the newest generation of cards to be maybe 10 amps above that, but I am just guessing.

For your spelling issues, just use a text editor (word etc) to compose your posts. Then use the spell checker on it and copy/paste it into your post.

Happy boxing.