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cmphal

macrumors newbie
Original poster
NOTE: This can be ignored or taken as an example of temperatures when one has installed the BOOST A and BOOST B fans in reverse. They were both pushing air in the wrong direction.


I am long time stalker of the mac-pro-4-1-5-1-aftermarket-fans-with-automatic-smc-control thread. I've been hoping for fans which same range as Apple original but quieter. While waiting I thought I would give the existing fans a good cleaning. Attached you will see the before and after temperatures of a unscientific test. Temperatures taken one hour into a handbrake transcode of the exact same file. I am concerned about the heatsink fans which seem to be running much higher. Also, prior to repasting, CPU B was always much cooler than CPU A.

This was my first time repasting a computer. I used duronaut. I did clean a lot of crud off the cpu board as well as considerable dust from the three heatsinks. Also, I learned that the upgraded 4,1 which I purchased 5 years back had lidded cpus rather than the de-lidded original configuration. So I'm also concerned that perhaps I have not tightened heatsinks appropriately or perhaps reversed the airflow on the booster fans when I reassembled.

Do before and after temperatures in the attached image look right or is it likely I have screwed things up? Any insights as to interpreting these temps will be appreciated.
 

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I have a 4,1 also. Firmware upgraded to 5,1 and it has lidded CPUs. Previous owner must have upgraded it.

My suggestion if your operation is stable, is stay away from the CPU heat sinks. One mistake overtightening, and your CPU board may be lost.

Your CPU-B temps are up, but not enough to cause a failure in my opinion. Fan speeds are generally up, with most temps down (the expected result). Looks to me like the SMC needs a day or three to recalibrate fan speeds vs temperatures.

Perhaps someone with more hardware experience will chime in. For myself, I'd leave well enough alone. Take fresh readings in a week at the soonest. An SMC reset might be useful in the meantime.
 
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