CPU Fan Keeps Ramping Up and Down

geo3 · October 18, 2019

31 minutes ago, amitkania said:

It works. So I think the temps are just rapidly changing causing the fan RPM to change.

Ok there are a couple things you can do.

1) Take note of the temperatures it fluctuating between and have the steep part of your curve be before of after that.

2) On my BIOS, also ASUS, there is a ramp up/down time setting for each fan. Setting is a number of seconds. Set it to something like 7 seconds or more. This will smooth out the spiky behavior.

amitkania · October 19, 2019

22 hours ago, geo3 said:

Ok there are a couple things you can do.

1) Take note of the temperatures it fluctuating between and have the steep part of your curve be before of after that.

2) On my BIOS, also ASUS, there is a ramp up/down time setting for each fan. Setting is a number of seconds. Set it to something like 7 seconds or more. This will smooth out the spiky behavior.

I just ended up buying a Gammax 400 aftermarket CPU cooler and my temps are 10C cooler now which seemed to have fix it.

moabdul123 · February 20, 2020

I had the same issue, what fixed it for me was syncing the fans with the system temp rather than the cpu temp. You should be able to do this through the bios (not quite sure how to do it on an asus motherboard as i have an msi board). CPU temps are constantly fluctuating when carrying out any task, idk why some motherboard have this on by default though. I hope this helps

chrisleeca · July 8, 2020

On 2/20/2020 at 3:20 PM, moabdul123 said:

I had the same issue, what fixed it for me was syncing the fans with the system temp rather than the cpu temp. You should be able to do this through the bios (not quite sure how to do it on an asus motherboard as i have an msi board). CPU temps are constantly fluctuating when carrying out any task, idk why some motherboard have this on by default though. I hope this helps

I wouldn't recommend this approach at least not for the CPU fan. Yes, it will remove the fluctuations but you are doing this by decoupling the fan from the CPU temps. So the CPU fan will no longer adjust cooling as the CPU gets hotter. Maybe for chassis fans this makes more sense, although the CPU still provides a more immediate indicator of system load. I also find fans ramping up and down is distracting, but a consistent noise less so. The recommendation from geo3 is right at least in my experience. Use HWMonitor to check what range of temperatures your CPU jumps between from idle to light work loads such as web browsing. Make sure you have a flat line on your fan curve over that CPU temperature range, so the fans are not ramping up and down constantly. Repeat the same with heavy workloads, such as playing games and set a steep ramp up in fan speed above the light work load temperature range. This approach has worked well for my own setup.