First of all, can I suggest you read the sticky? It really has got an awful lot of excellent advice in it (and I'm not just saying it because I wrote big chunks of it ) Secondly, if you want to fit this all in one case you're better off with a single loop. It is possible to get better performance by running the graphics cards in a second loop (graphics cards tend to be happier running hot than CPUs, so need less cooling) but you'll end up needing an enormous area with access to fresh air to cool both radiators. If you have that, great, but remember you're going to need an enormous case. Virtually all the special "watercooling fluids" on sale are in fact water with small amounts of antifreeze as an anti-corrosion additive and an biocide added, and actually perform slightly worse than water. The anti-corrosion is not needed if you pick the materials exposed to water carefully - I've been running a loop with only copper, plastic and brass exposed to water for 5 years now, with no anti-corrosion additive and no corrosion at all. The biocide is needed however - the nice warm water in your loop will otherwise start to sprout all sorts of interesting bacteria if you don't add it, and they will gunk up the system. Deionised water (normally safe if you pour it all over your computer) is available cheaply for topping up car batteries from most places selling car parts, etc. - you can use tap water, but this is slightly more of a risk if you spill it on your PC. At this point, I suggest you start looking at cases suitable for fitting a 3 x 120mm radiator, and start planning from there. For comparison I'm currently cooling a Core i7-920 plus a single Radeon 4870 with a single Thermochill PA.160 (an oversized single 120mm fan radiator), and a single thermally controlled low noise fan. Limited overclocking headroom as is, but virtually silent - my central heating is louder, and the boiler is on the other side of the house!