Quote Originally Posted by gabe View Post

Under typical computer use, the above test data suggests as a general rule that users would not benefit from setting up dedicated loops for CPU and GPU. Serializing pumps in the same loop also adds a redundancy factor that dedicated loops cannot provide. With superior reliability and lower temperatures at both CPU and GPU levels, single loops appear to win hands down.

Under extreme computer use, this setup recorded a notable advantage at the CPU temperature level for the dual loop, counterbalanced by the opposite effect at the GPU level. This extreme environment uncovered the critical importance of the respective load ratios generated by CPU class devices vs. GPU class devices, relative to the heat exchangers to which they are connected. Clearly, a CPU generating 150 Watts solely dedicated to a triple radiator will cool substantially better than when mixed with another 400 watts generated by two GPU's even with a second dual radiator in the loop.
Gabe with all due respect it appears your single loop apparently cures all that this thread has turned into, actually only applies to typical computer use mildly overclocked with a CPU and Single GPU in the loop and completely discounts the test numbers you ran yourself, in the first set of tests in your .pdf paper.

One single loop is based on the assumption all of us are satisfied with Typical Computer use, disregarding the fact that some of us water cool our CPUs for the maximum possible CPU overclock we can stably reach, some of us even went to water cooling specifically to cool the Sandy Bridge CPUs to be able to stably reach a 24/7 5ghz overclock.

Granted that's not typical computer use at all, I'll give you that!, but from my own experience, I could not reach a 5ghz CPU overclock running 2 full coverage overclocked 580GTX in SLI in a single loop, so for myself that's why I split my setup into 2 loops, and once the Sandy Bridge was on it's own loop, a 5ghz stable overclock was then attainable.

Your own first series of test result numbers plainly show a high CPU overclock and multiple GPUs put you at a disadvantage with your own i7-920 tested at 4095mhz a 1430mhz overclock, (Which was actually kinda on the tame side since some went way past that with air cooling), and I'll venture to say that with a 2nd,3rd,and 4th, generation Intel CPU a 1430mhz overclock from stock would show even higher numbers than you reached in your own tests.

This thread now seems flooded with single loop flag wavers completely discounting your own established test numbers, so shouldn't you make a distinction that this does not apply to those seeking as high a stable CPU overclock as they could possibly reach, especially with a Ivy Bridge or Haswell CPU, as these test numbers are already old information with an i7-920?

For the record we all know Ivy bridge and Haswell is an even hotter overclock than Sandy Bridge was, so for those truly seeking as high a CPU overclock as they can possibly stably reach using radiator water cooling, I am going to say combining that high CPU overclock with multiple GPUs in the same loop will limit the CPUs possible overclock.

Taking your own test numbers into account do you at least agree with that statement?

This is Xtreme Systems forum isn't it, maybe I'm in the wrong forum?

Thank you for your time and consideration. RyNemesis