Need clarification on CPU fan speed control

[dc4517]

When I built my PC, I left the CPU fan at 100% because I wasn't sure whether I had installed my Hyper 212+ properly. Actually, I was more concerned about my application of the thermal paste due to the uneven surface from the heatpipes. So I wanted to make sure the CPU was getting the most cooling possible.

From time to time, I've been looking at ASRock's OC Tuner program to monitor all the system readings. Temps at idle have been 23C/73F. At load while running Handbrake (the only intense thing I've run so far), it went up to 30C/86F. Are these normal for a i5-760?

Anyhow, my main question is for the CPU fan speed control. I went into BIOS to change it from Full On to Automatic with the target CPU temp being 50C/122F and target CPU fan speed at Level 5. Fan is running at 1150-1200 RPM now. What do these target values really mean? Will the fan start spinning faster if the CPU temp goes over 50C/122F?

 

[SirGCal]

I haven't hard-locked the CPU fan speed for many years. The auto control will speed up the fan as the chip heats up, keeping noise down. Your temps look very nice but it's at max cooling obviously. With current CPUs, I'd say anything under 60C is acceptable. Your cooler is a very capable unit. Let the BIOS handle it. What the level settings are for specifically I'd have to investigate your particular motherboard to know for sure but, even overclocking, I usually just leave it on auto.

 

[IGemini]

I'd say your temps look pretty good. If there's a problem with cooler contact, maxing out the fan won't help that much. It'll cycle a lot of air but it won't do much if the heatsink can't transfer all the heat away from the CPU. Improper paste & contact will generally result in high idle temps (40-45C or more).

The ASRock manual doesn't help much for those BIOS settings...if I had to guess, it's set to throttle the fan to 100% if it hits 50C. No idea about "Level 5."

 

[dc4517]

After playing around with the settings some more, I've decided to leave it at Level 5. Level 10 has the fan spinning at 2000 RPM and you can definitely hear it. At Level 5, I don't hear the fan, and it keeps the CPU running pretty cool. I was running Handbrake again this evening and even at Level 5, the CPU only rose up to 30C/86F. So it was the same as Level 10. I have to say how impressed I am with the Hyper 212+. Great performance at a low cost.

I haven't been able to hit the target CPU temps, so I don't know yet what happens when I do. I guess I shouldn't worry about, eh?

 

[deimos3428]

Those temps are quite good for a modest air-cooled system; you don't even need to think about worrying until 50C. According to the Intel spec sheet, the rated maximum temperature for your CPU is 72.7C, but I'd keep at least 10C under that.

http://ark.intel.com/Product.aspx?id=48496

For extra piece of mind, set your fan to the speed you're comfortable with and simulate a worst case scenario with an overclocking tool like Prime95 or OCCT, etc. These will put your CPU at 100% utilization, and your CPU temp will go up significantly. Keep a close eye on the temperature, and stop the tool if it exceeds 62C. As long as the temperature settles under that, your cooling can be considered sufficient under any normal operation.

 

[dc4517]

Actually, I did try Prime95 last night and after running for about 15 minutes (it was late and needed to go to sleep), temps got up to about 35C/95F while my fan was running around 1200 RPM (level 5). After I stopped running it, it dropped back to 23C/73F within 2 minutes. I'll try running it longer tonight and see where it goes.

 

[IGemini]

Yup, I'd say your cooling is running pretty well. Prime95 doesn't really start pushing the CPU until at least an hour or two in, you'll probably see temps going into 45C around that point, well-within what that processor can handle under load.

 

[deimos3428]

35C is almost *too* good for full load, isn't it? I'm not all that familiar with modern Intel chips but it seems quite impressive.