Disconnecting CPU from loop and leaving GPUs

[blade52x]

I tore down my loop this weekend and am running everything on air right now, with a H60 on the CPU. I've been measuring power draw of my Titans in SLI at 1100/6600 to be typically between 550-600W from the wall. But I have seen spikes as high as 700-750W. I've seen a single Titan draw as much as 500W when overclocked to 1320/7000. I actually have to get a new PSU (hopefully this BF) because the Titans further overclocked (to say 1202/7000) will overload my 850W PSU (and a quality one at that) in specific scenarios and cause it to shut down. That is how much power the Titans can draw, so is not like your typical 1x CPU + 2x GPU of the past.

I have 360 and 240 radiator now. I am considering removing the CPU from the loop, because what I've seen in the past (with just a single Titan), was the CPU reaching 70C+ easily in gaming sessions. Everything in the loop would become very warm to the touch after 15-20 minutes. This was with maybe 450W sustained being drawn from the wall. The benefits of water cooling the CPU became negated. The CPU performed amazingly in the loop by itself when the Titan was idle, but it doesn't quite dump the same amount of heat out into the loop as the GPU let alone GPU + CPU. Once the loop became warm (and stable), the CPU would actually perform on par with an AIO. Now I'll be aiming at 700W+ sustained into the loop, and I can only imagine that would things a lot worse for the CPU, and cause it actually perform worse than with just an AIO.

My temperatures were something along the lines of (during the warmer months, room around 25-30C)
Everything idle : CPU 27-32C, Titan 32-35C
CPU load, GPU idle : CPU 58-65C, Titan ~35C.
Gaming sessions : CPU 70C+, Titan 50-55C.

Now I'm adding a second GPU and I feel this may just get worse for the CPU, so am considering removing the CPU from the loop entirely and just running it off a H60 (which is actually performing very well with CLU on the die).

Does anyone else do this, or does this even make sense?

 

[Kardonxt]

Made the same move a while ago myself.

I stopped water cooling my CPUs when my first 2600k build only gave me another 200mhz 24/7 over the hyper 212+ I had on it while I waited for my block to come.

I only watercool my gpus now as they still seem to benefit a lot noise, heat, and OC wise. Unless you move over to a 6 core build it doesn't seem sandybridge on up produce enough heat to justify WCing them.

Edit: I'm not sure it would help your cpu temps greatly but I don't think its going to hurt in terms of performance.

 

[blade52x]

Well, the H60 gives me about 65-70C full load right now. I was testing a C++ fully threaded program that ran for about 30 minutes before returning a solution. It's no so much SB/IB not requiring water cooling, but more that I'm seeing GPUs actually hinder SB/IB temperatures because of how much heat they dump into the loop. That's why I'm considering splitting them. Because if I do, I know the GPUs will no longer effect the temperature the CPU operates at. I'm not going to get more or less performance out of my chip. Another 100-200mhz and it starts getting pretty unstable despite giving it a good amount more voltage. The H60 handles 4.6ghz beautifully, but again likely because I put CLU under the heat spreader to address the Intel crap TIM issue.

 

[bpmcleod]

What is the clock of your titan? What rads are you using and with what fans to push air? Water is still the ovrrall better choice betwren air and water. If you havr enough rad space to dissapate the heat being generated then keep the cpu in the loop. A single 360 can "handle" you titan and cpu with good ocs and nothing crazy as most 360 rads have a TDP in the high 600s. That being said you still need good fans pushing the air through and good fans pulling it out of the case. And besidea, 70c is nothing .