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Fans forced to 100% when CPU reaches 75C

TamiyaGuy
Level 7
Been using a PRIME Z270-A, along with an i7 7700K, for a little while and I've got to say that as my first Asus product, I'm pretty disappointed. I've noticed that in both BIOS and AI Suite III fan control options, the fans attached to the motherboard force themselves to 100% speed when the CPU reaches 75 degrees Centigrade, and there doesn't seem to be any way to fix this. Having bought Asus specifically for their reputation in fan control options, and seeing other options like the "Extreme Quiet" PWM option and fan spin-up/spin-down time variation, this seems like a really strange limitation for two reasons:

1) Competitors seem to offer much broader temperature control. MSI allows at least 85C, Asrock seems to allow 90C, and Gigabyte allows full control up to 100C. So why is Asus so behind the competition in this, especially in this day of both silent systems and easy overclocking?

2) Intel themselves have said that a 7700K reaching 75 - 80C is "considered expected and normal". So why is Asus ramping up every fan in my system to 100% as if it's some kind of critical temperature?

Is there any way to bypass this limit? I've tried both in the AI Suite III application and by modifying the saved profiles within the application folder, but neither seem to work.
7,903 Views
44 REPLIES 44

Chino wrote:
You can control the fan curve in AI Suite III or the BIOS.


Unfortuantely, I can't adjust them beyond 75C, either in the BIOS or AI Suite III. Please see the attached screenshots: I cannot move the far-right circle any more to the right, and any other attempts to change the fan speed don't work.

65092

65093

Hi,

I aquired a Strix Z270F myself, and been suprised by this limitation too, and I have to add that the "CPU fan step up" and "CPU fan step down" settings in the bios are not working (tried with DC and PWM fans).

Can we expect a bios upgrade ?

Aghoithae wrote:
Hi,

I aquired a Strix Z270F myself, and been suprised by this limitation too, and I have to add that the "CPU fan step up" and "CPU fan step down" settings in the bios are not working (tried with DC and PWM fans).

Can we expect a bios upgrade ?


Well I have noticed that while the BIOS seems utterly limited to 75C (entering anything more than that in the "[Fan] Critical Temperature" field found in the advanced Q-Fan menu results in an error message and being reset to 75C) the latest version of AI Suite III does allow you to set a custom critical temperature above 75C for case fans. For some strange reason you can't do the same for the CPU fan, but I suppose it's better than nothing. Helps keep my 1500rpm case fans at bay, at the very least.

I really wish we could have this limit raised to 85-90C seeing as 7700k can easily spike to 85C under heavy load without any OC at all.
That makes the fans go totally crazy..

PadmaN wrote:
I really wish we could have this limit raised to 85-90C seeing as 7700k can easily spike to 85C under heavy load without any OC at all.
That makes the fans go totally crazy..


Me too. And I've checked on a friend's computer - MSI motherboards allow CPU fan control up to 100C as well. I'm getting the impression that I bought an unfinished product here...

Oh well, I daresay if the people who are annoyed by it make enough noise about it, it'll be put on the wishlist for the next BIOS/AI Suite III version. One can hope.

Here's another guy wishing for higher "critical" temp allowed on the CPU than 75C.

75C is easy street for any modern chip; at least some Intel chips have Tj values upwards of 120C, and even 100C should - while not preferable - not be terribly dangerous either. Certainly anything below 90C doesn't warrant spiking the CPU fan to max! Especially not big brute dual 140mm CPU fans like I have invested in... UGH! 🙂

In the same vein, how about letting us freely configure the 4-pin pump power headers as fan headers instead? I can't rename the pump headers, nor set a fan location in the Fan Xpert software, which is inconvenient. I don't see why it has to be so difficult. 😛

TamiyaGuy wrote:
Me too. And I've checked on a friend's computer - MSI motherboards allow CPU fan control up to 100C as well. I'm getting the impression that I bought an unfinished product here...

Oh well, I daresay if the people who are annoyed by it make enough noise about it, it'll be put on the wishlist for the next BIOS/AI Suite III version. One can hope.


I've unplugged my AIO cooler fans from the CPU pump header and disabled monitoring for that header in the BIOS. I have the radiator fans plugged into chassis 2 and this gives fan control up to 100 degrees (when you check the critical temp box in ai suite).

It would be FAR more elegant for ASUS to just fix this in the BIOS and make the CPU FAN control up to 100 degrees.

It bugs the hell out of me that AI suite shows my CPU fans with big red 0000rpm.

Not really a pro overclocking motherboard if you have to do an ugly fix like this - it's almost like they encourage delidding!

I actually recommended to a friend that he buy an MSI board for his new PC because of this issue.

Dude1070
Level 8
Did you guys use the Fan tuning option in the BIOS or AI Suite? That opens it up for settings.