Single WaterCooling Radiator for one full loop

This is my new and second computer which I am working right now. I have collected several parts from the primary rig and soon will play around with those here. I am looking at Core i7 950 at 4.2GHz along with a R3E waterblock. I also want to configure 4 8800 ultras (3 will be in SLI and one will be as physics). What my intention is to complete the entire configuration in one full loop but with the use of very small radiator if possible. Currenrly I have 2 120x4 (Black Ice GTX480) and 2 120x3 (Black Ice GTX360). Is it possible to run a Whole loop with single radiator or should I need to add 2.

By looking at your configuration and specification I can get that you will at least need two big radiators. I have lot of experience with system configuration and I have seen that 4 8800 Ultras and an older i7 overclocked can produce much heat. So it could be better to do a good watercooling rather than making it less.

You will need some form of serious watercooling for those components and for overclocking. If the CPU's and GPU's are smaller, then that means fewer temps. In my case I had a single 120.2 rad in push/pull cooling which is configured for i5 2500K at 4.9GHz and for two overclocked GTX 570's and one GTX 560 Ti. So far I have never seen temps raised above 73C for the CPU and the GPU temp was always lower than 55C during load. So it was always the safe running.

Rather than choosing the size, I will be concerned more about the capacity of the radiator. This is what we needed the most. I think that you can run single GPU and single CPU using 240mm radiator but it wouldn’t be better for overclocking or something else. You will need at least 120mm of rad space for each block in a loop. Also running single radiator for different components always causes issue. That is if you are going to choose the CPU before the GPU and put the radiator after the GPU in the loop, the temps or heat produced from the CPU might increase the GPU temps. However if you configure as CPU > Rad > GPU, the heat from GPU pass through the reservoir to the CPU. So there is always a chance that one of your components getting damaged.

No matter what you choose, just keep in mind that you have the powerful pump in order to run a loop and also make sure that there is no massive climb. If you are not sure about how much power you need for pump, just do the calculations of required LPH for a loop.

You are planning to run SLI/CF. In that case I recommend you to run run either dual loops or try to get lot more radiator space and also run each radiator after each component which you want to be watercooled. Get a decent pump for that. Most people don’t use enough radiators thinking that their pimp is not powerful enough to handle it. If you are using 4 GPUs, then it can be count as one component. For dual GPU, there is no problem without a radiator in between. Make sure that a radiator is configured after the GPU's and also radiator after the CPU

I think that you can do all with single radiator but make sure that it completely depends on the overclocking plans. Also it is based on the type of radiator and fans being used. At stock speeds, it may be possible even with overclocking.