If you're overclocking the processor more than 5-10% an aftermarket cooler is a good idea.

As for motherboards, the only board that does SLI, 775socket CPU and DDR3 is the 790i (there's a couple of different flavours, but they're all 790i and not cheap).

The X58 does DDR3 and SLI but only takes the new nehalem CPUs. Fantastic performance but nehalem is way too expensive.

The 780i, 750i and 680i do SLI and a Q6600, but are only DDR2. 780i takes 3-way SLI and 'new' intel quads like the Q9450. The 750i takes 2-way SLI and 'new' intel quads like the Q9450. The 680i takes 2-way SLI out of the box, older intel quads like the Q6600 and 'new' intel duals like the E8400.

If I were you I'd go with DDR2 and the EVGA 750i motherboard.

ok i think i will go with the EVGA 750i that you suggested thanks. Btw do you know what the differences are between DDR2 and DDR3 i just heard DDR3 is way Faster then DDR2 Am i right?

It is faster, and more expensive. DDR2 has lower latencies, but DDR3's speed makes up for this.

Since most intel CPUs have locked multipliers, you have to do some serious overclocking to get your FSB up to somewhere near the RAM speed. So with DDR3 the RAM is really outpacing the rest of the system (a large divider ratio).

Some people report a performance difference, but I'm sceptical. The only reason to go DDR3 in my opinion is if you're doing Nehalem, which would mean money is no object.

If you've got any questions about the 750i or any other SLI related queries I recommend asking the people at SLIzone.

I have to point out that Intel chipsets (non-SLI) do overclock better than NVidia ones. The P45, for example, will overclock higher but doesn't do SLI.

PS: oh yeah, get the 750i FTW edition if you're going 750i. It's got solid state capacitors for longer life. http://www.evga.com/articles/401.asp

thank you so much i have given you +rep

i will go with that it sounds good and its not to pricey. Then in a couple of years, the price might of gone done for the Nehalem processors, and i might buy one of them.

Thanks, I think you've made a good choice

Just be aware that a Nahalem CPU needs a Nahalem motherboard. Only the X58 motherboard currently supports Nahalem.

Ok thanks Again!