Hows my rig? Will I have any heat issues with the dual GPU's and the OC'd CPU? also is there enough connectors for dual gpu's with this PSU?
i5-750 (want to overclock to at least 3.6ghz) x2 HIS Radeon HD 5850 (might try to oc, but i dont thk its necessary)
4g G Skills 1600mhz memory Antec case (1 x 120mm rear fan / 2 x 120mm front fans / 140mm blue fan top fan) Antec PSU 650w
MSI P55-GD65 Mobo
I highly recommend this PSU. It is more expensive, but if you're crossfiring two 5850s and overclocking, I think you might want to. At 3.6 ghz you may be able to get away with the stock Intel cooler, but an aftermarket CPU cooler is likely the best bet.
The Antec 300 illusion is a great case, you wont have any problem with a good 120mm air cooler. You dont want to use the stock cooler on an i5 750 if you are going to overclock much.
You should read the CPU articles here, Toms reviewer found that leaving turbo mode on and overclocking the i5 750 to 3.2 gave as good performance with less power and heat than running at 3.6 with turbo off. (They couldnt get 3.6 with turbo on stable without significant voltage increases and they were avoiding that in the article).
The i5 760 is out now and starts at 2.8GhZ for not much more $$ (the i5 750 starts at 2.66GHz).
I dont think the Antec EA650 or Corsair TX650 is going to cut it with a pair of either 460s or 5850s (power usage is almost identical). Both PSUs only have 2 PCIE power cables and you will need 4. (460s do seem to be a better deal right now).
You will have to move up to at least an Antec TP650 or Corsair HX650 (which have 4 cables and more 12V wattage) or preferably a 750W model since you plan on overclocking also.
the 650w can handle 2 5850's and 2 460's no problem he only needs to use the converters with the gpu
let me explain 2 gtx 460's use 500w under load + 100w for the cpu + 30w for everything else that's a total of 630w but this is the total of what the psu takes from the wall which means the psu will only be outputting 580w or something like that plus the pc will never be put at 1oo% load on every component plus the peak power of the antec is about 720w or something
Notice I gave a couple 650W models that would be OK. Its not the wattage as much as the 12V amperage that is the issue. The EA650 has less 12V wattage than the TP650. Both have 650W but its distributed differently along the rails. I dont recommend using the converters on a new build because the manufacturer obviously didnt design that PSU for that use. Its an unnecessary risk when there are so many safer options.
In any case getting a 750W PSU is a safer idea. PSU capacitors age and the output drops off. If you get one too close to max system power, it will start to fail in a year or two. A good one with some extra capacity can last several years.
Now I have to do my spiel about how much I like the looks of my 900 case, but after getting a 300 illusion for my kids gaming PC I wont get another 900. The dust filter on the 300 illusion is such a nice feature; I would only get a 300 illusion, 902 or 1200 (all have dust filters).