Originally Posted by Martinm210
Sorry I wasn't clear, I was trying to answer the CPU + SLI GPU Loaded at the same time question and thought the poster was referring to system 5 "At the end" which I noted in my response. I thought sys4 and 5 both were running 680s and missed the 7970s were running on the last system.Perhaps I missed it?, but was system 4 loading GPU also??
I heard that burn test was being used, but I didn't hear anything about a GPU benchmark running concurrently.
Regardless, I was trying to figure it out using C/W and heat loads and cobbled together the following:
At 1200RPM an MCR220 has about a .095C/W
Assuming a 130W processor and two 195W video cards can add to upwards of 500W. Even if you reduce that to 80%, it's still a massive 400W worth of heat. Granted there isn't much data on "REAL LIFE HEAT LOADS", so going off a guess here and assuming 80% of max is a good guess.
400W * .095C/W = 38C, that is really way too high, you would definitely need higher fan speed..
At 2000RPM however the C/W gets much better at a .035C/W, 400W * .035C/W = 14C (still too high for my liking)
The kit fans run up to 1800RPM, so the C/W value must be between the .035 and .095. The change is .06C/W over 800RPM or .0075C/W per 100RPM. To estimate the 1800RPM I will take the .035C/W value and add .0075C/W x 2 or a C/W = .05
Now back to the assumed 400W heat load.
400W x .05C/W = 20C.
To get a 10C delta (which I would consider a good average), I would think you need to add one more MCR220QP and use full 1800RPM speeds which is more in line with the system 5 setup which is what I would do..
Actually I like a quad rad per component (Silence and a 5C water delta), but that gets tough keeping INSIDE a case..