Fans forced to 100% when CPU reaches 75C

[TamiyaGuy]

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.

[Silent_Scone]

Jsunn wrote:
So you are saying that the fan curves in the BIOS are NOT based on CPU temp? This doesn't seem accurate to me. All of my fans will ramp up and down based on CPU temp.

What do you mean by Tcase?
Sorry for the basic question.

Thanks,
Jason

See here for more information on Tcase. Given the fact this reading can be 10-15 Celsius lower than DTS as stated in my previous post, the CPU is likely running quite hot. Therefore, there is little reason to need a higher limit on the curve control.

Tcase: Temperature measurement using a thermocouple embedded in the center of the heat spreader. This initial measurement is done at the factory. Post-manufacturing, the BIOS calibrates Tcase. A diode between and below the cores delivers a reading.

https://www.intel.co.uk/content/www/uk/en/support/articles/000005597/processors.html

[RidingTheFlow]

Registered just to chip in, since I've bought an Asus Prime Z270A motherboard recently and was totally baffled when I saw this.

Silent Scone wrote:
This is a Tcase reading that is utilized for fan curve control.

This is not entirely accurate for modern mainboards. Intel got rid of TCase since 7th generation - mainly because it was not possible to use as accurate measurement. TCase required specially-modified heatsink and "software offset" in BIOS never worked that well.

So they switched to using solely TJunction/core temperature sensors. Modern CPU datasheets only spec the TJunction max and not a TCase (since there are no means to even know TCase anymore).

E.g. both Z270 boards I had report "CPU temperature" in BIOS via "PECI" interface - which is basically average of core temps, which can reach 90-degrees during normal operation without any thermal throttling.

More details here - http://www.tomshardware.co.uk/forum/id-1800828/intel-temperature-guide.html


In any case, 75 degree max for fan curve is just arbitrary and low restriction. Why is it even here? Is it to protect the user from doing stupid things? I remind you this is "gaming" motherboard, and it already have much more dangerous CPU-destroying options like voltage overclocks and so on. Not to mention that its not really possible to damage modern Intel CPU even by switching fan off - as long as heatsink is present, it will simply throttle to low speed (since it has enough TDP on low speed for passive cooling).

I find it ridiculous that Asus gaming motherboard fan control is full of such arbitrary restrictions. E.g. you can only control Pump header speed from CPU temperature - why is that? Its just another header, third party software (like Speedfan or Argus Monitor) can control it like any other header from any source, but no, Asus thinks it must be arbitrary restricted just because they named it "Pump".

Asus, please remove these restrictions. No competitor board I've tested have these. I want to be able to use high temperatures for fan curve points, since air cooling most efficient/quietest with hottest heatsinks. Now I have to use third-party software to override BIOS or make hacked BIOS to to this.

Aghoithae wrote:

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).
?

And yeah Asus, please fix fan speed change delays too. They don't really work and don't serve their main purpose - they don't prevent abrupt fan speed changes on fast temperature spikes (common with Kaby lake CPUs for example). This causes unnecessary noise and wear as PWM fans are forced to abruptly change speed.

[Silent_Scone]

RidingTheFlow wrote:
Registered just to chip in, since I've bought an Asus Prime Z270A motherboard recently and was totally baffled when I saw this.


This is not entirely accurate for modern mainboards. Intel got rid of TCase since 7th generation - mainly because it was not possible to use as accurate measurement. TCase required specially-modified heatsink and "software offset" in BIOS never worked that well.

So they switched to using solely TJunction/core temperature sensors. Modern CPU datasheets only spec the TJunction max and not a TCase (since there are no means to even know TCase anymore).

E.g. both Z270 boards I had report "CPU temperature" in BIOS via "c" interface - which is basically average of core temps, which can reach 90-degrees during normal operation without any thermal throttling.

More details here - http://www.tomshardware.co.uk/forum/id-1800828/intel-temperature-guide.html


In any case, 75 degree max for fan curve is just arbitrary and low restriction. Why is it even here? Is it to protect the user from doing stupid things? I remind you this is "gaming" motherboard, and it already have much more dangerous CPU-destroying options like voltage overclocks and so on. Not to mention that its not really possible to damage modern Intel CPU even by switching fan off - as long as heatsink is present, it will simply throttle to low speed (since it has enough TDP on low speed for passive cooling).

I find it ridiculous that Asus gaming motherboard fan control is full of such arbitrary restrictions. E.g. you can only control Pump header speed from CPU temperature - why is that? Its just another header, third party software (like Speedfan or Argus Monitor) can control it like any other header from any source, but no, Asus thinks it must be arbitrary restricted just because they named it "Pump".

Asus, please remove these restrictions. No competitor board I've tested have these. I want to be able to use high temperatures for fan curve points, since air cooling most efficient/quietest with hottest heatsinks. Now I have to use third-party software to override BIOS or make hacked BIOS to to this.


And yeah Asus, please fix fan speed change delays too. They don't really work and don't serve their main purpose - they don't prevent abrupt fan speed changes on fast temperature spikes (common with Kaby lake CPUs for example). This causes unnecessary noise and wear as PWM fans are forced to abruptly change speed.

You're misinterpreting the information in the link. The vendors calibrate the offset themselves via placing a diode on the IHS. PECI is used, however, if the IHS temp is at 75c, core temps will be anywhere between 10 to 15 degrees Celsius higher. So I'm not sure why you feel you'd need more range than this. You can make all the noise about this you want, but given the above there is nothing wrong with the limit implemented.

[RidingTheFlow]

Silent Scone wrote:
PECI is used, however, if the IHS temp is at 75c, core temps will be anywhere between 10 to 15 degrees Celsius higher.

This is factually wrong at least for two different Z270 motherboards I've personally tested.

Right at this moment I have Prime Z270-A running burn test with 7700K (BIOS 1009) and PECI reported CPU temperature is almost exactly same as max/average temp of 4 cores, running at ~92 degree at full speed.
Motherboard also clearly peaks fan at 100% RPM when cores reach around ~75 degree.

There is no 10-15 degree offset. Idle temps are the also same.

[RidingTheFlow]

Also, I have to add, even if there would be 10-15 degree offset to CPU temperature on some motherboard, this will place maximum around 85-90 degrees - which for me still will be not enough. I want maximum at least around TJmax, which was how PECI actually designed (since it actually internally reports temp as negative relative to TJmax so fan can go at max when it reaches zero), especially for high-RPM PWM fans.

Also all this CPU temp offset discussion is entirely irrelevant for cases like using thermistor probes as fan source - there will be no offset there and it makes also impossible to peak fan, if, for example your GPU reaches at least 85 degrees.

[Silent_Scone]

The value is averaged.

1) It is sensible to have some buffer to account for variance.

2) You'd struggle to put a temp probe on a GPU in a way where there would be no offset.

[RidingTheFlow]

Silent Scone wrote:
The value is averaged.

It looks more like a core with max temperature to me, not average.

1) It is sensible to have some buffer to account for variance.

I don't want "buffer" of 25 degrees. If some core spikes to 100 degrees, I prefer it to throttle momentarily until fan catches up, not have fan spike to max at 75 degrees.

2) You'd struggle to put a temp probe on a GPU in a way where there would be no offset.

It about 5 degree max offset for my setup (thin strip probes between heatsink and PCB). Maxing out fan at 80 degrees is too low for me.

Anyway, you are making a lot of explanations why I should not want or need things I want to do.
I thought enthusiast-grade products are about giving enthusiast maximum flexibility about their methods, not hand-holding.

If you don't need points about 75 degrees on your fan curve, you are free not to use them.
However, would be nice if I didn't need to return this ASUS motherboard and switch to competitor just because somebody at ASUS decided that "75 degrees max should be enough for everyone".

[EtoEgor]

bump

[blakeredfield]

Hi everyone,

Wanted to share my solution to this problem, for my setup:

ASUS ROG Maximus Hero Alpha VIII
Intel 6700k @4GHz (no OC yet)
Corsair H115i
Nvidia 970 x 2 SLI
Windows 7 *difficult to install, another story

1. Install Corsair Link H115i to install the correct drivers. Then uninstalled. Connected CPU Fan to Motherboard.
2. Find (!) and Install AI_Suite_III_3.00.13_DIP5_1.05.13.zip which has the feature which allows 75C max to be overridden.
3. Install AI Suite 3, which apparently is called Dual Intelligent Processors 5 - not complicated at all, thank you ASUS - and run Fan Tuning to get DIP 5 to read the headers.
4. Hit the tick mark and set as shown.

Note 1: If you're not seeing the CPU fans, go into your Motherboard Settings, turn on PWM options under Monitor where you can. If you have a Q-Fan or other Fan configuration tool, set its options to AUTO, if available. We just want to give the OS the option of picking up the motherboard settings. It might take some tweaking.

Note 2: When I first installed Win7, I had to install the most recent Chipset drivers AND Run Windows Update before all of the headers appeared on Corsair Link. I used it to make sure the OS was reading the temperatures. Once I saw them all, I uninstalled Corsair Link - good riddens!

Note 3: You might not like when I'm showing in the screenshot, which has my fans only turn on when the CPU temp hits 100C. If you have an AIO Liquid Cooling solution the heat is already being dissipated by the liquid heat exchanger pump and dissipated away by the air flow inside my case which already has 6 fans - 3 pulling in and 3 pushing out, excluding video cards which only turn on when needed. My CPU temperature comes up to about 88-92 C during gaming, never higher and the CPU fan has never come on since making this adjustment, even after hours of gaming. Tune yours any way you want.

[6kbyte]

Are there any updates here? Did Asus fix the problem (by BIOS/official AI-Suite update) that fans beeing forced at 100% when the cpu reaches 75C/76C?

Iam thinkig about to buy a "Asus ROG Z390 Maximus XI Hero WiFi" but if Asus didnt fixed the Fan-Issue i will go for a ""ASRock Z390 Phantom Gaming 9".