Question Bios Q Fan speeds are inaccurate.

May 16, 2023
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Really having a tough time figuring this out guys. Any insight would be amazing. A set a fan curve with Asus motherboards Q Fan settings. I use Core Temp to monitor my CPU temps. My fan curve is set to 40% speed from 0c to 60c. Then from 60c to 70c it goes to 100% speed. But my fans only go past 40% at 70c and 100% at 80c. I tried lowering the same curve. 40% at 50c to 100% at 60c. The fans then only go past 40% at 60c and hit 100% at 70c. It's seems that Q Fan thinks I'm always exactly 10c cooler than what my Core Temp app is telling me. So to get the exact fan curve I want, I have to tell Q Fan to kick in 10c cooler than what I really want to achieve my desired fan curve. Hope that makes sense. Thanks for any help you can offer.
 

Paperdoc

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The % numbers are NOT precise! In fact, the % numbers for most such systems are the % of maximum electrical power being fed to the motor, according to the "% ON" value of the PWM control wave signal. What actual speed this produces in the motor is NOT the SAME percentage of the motor's maximum speed rating. About the only time they might match is at 100%, and maybe not even then because of some fan motor designs.

As an aside, we all talk about fan SPEED control. But the truth is all the control systems are really TEMPERATURE controls. That is, their sole focus is on the TEMPERATURE as measured by a relevant sensor - for example, the sensor built into the CPU chip for the CPU_FAN control system. The system manipulates the speed of the fan to get whatever air flow it takes to get the measured temperature to meet the current target, and it really does NOT care what that fan speed is. If the temp goes up, the system simply sends more power to the fan until the temp goes back to where it should be.
 
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ReveurGAM

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Sep 28, 2022
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Are you using Asus Armoury Crate? If yes, do NOT use the fan auto-tuner as it will take full control of your fans and not let you control them via BIOS AND Armoury Crate itself. Even if you uninstall Armoury Crate, the app that does that will not be removed. In addition, if you have high-RPM, it will nerf their RPMs dramatically.

If you did, the fan app is removable, but you must first stop it in task manager, and disable it in startups, and restart. If that doesn't work, you'll have to do that again and uninstall Armoury Crate completely. It is very tenacious!
 
Hi Guy's
Asus has a uninstall tool.
You will have to look on the support page for your mobo.
Here is a page to help you


I had Am Crate installed but had to remove it because it made Ghost Recon Wildlands totally unplayable on my system so digging around I found the uninstaller and everything is fine now.

Here is a good utility that has been working for me to adjust from within windows.
View: https://m.youtube.com/watch?v=uDPKVKBMQU8&feature=youtu.be
 
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May 16, 2023
4
2
10
Are you using Asus Armoury Crate? If yes, do NOT use the fan auto-tuner as it will take full control of your fans and not let you control them via BIOS AND Armoury Crate itself. Even if you uninstall Armoury Crate, the app that does that will not be removed. In addition, if you have high-RPM, it will nerf their RPMs dramatically.

If you did, the fan app is removable, but you must first stop it in task manager, and disable it in startups, and restart. If that doesn't work, you'll have to do that again and uninstall Armoury Crate completely. It is very tenacious!
Thanks for your reply man. I always disable Armoury Crate before every fresh windows install. I actually thought of that too and double checked before I posted here.
 
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  • Like
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May 16, 2023
4
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The % numbers are NOT precise! In fact, the % numbers for most such systems are the % of maximum electrical power being fed to the motor, according to the "% ON" value of the PWM control wave signal. What actual speed this produces in the motor is NOT the SAME percentage of the motor's maximum speed rating. About the only time they might match is at 100%, and maybe not even then because of some fan motor designs.

As an aside, we all talk about fan SPEED control. But the truth is all the control systems are really TEMPERATURE controls. That is, their sole focus is no the TEMPERATURE as measured by a relevant sensor - for example, the sensor built into the CPU chip for the CPU_FAN control system. The system manipulates the speed of the fan to get whatever air flow it takes to get the measured temperature to meet the current target, and it really does NOT care what that fan speed is. If the temp goes up, the system simply sends more power to the fan until the temp goes back to where it should be.
Very nice dude, I appreciate the thorough explanation. I feel this is exactly what's going on and I just didn't understand how it all worked. I'm only a few years into building PC's and I got a lot to learn. Do you think my original fan curve was ok then? I was just worried my chassis and CPU fans weren't kicking in on time when I really needed it. Sorry if I sound like I still don't understand. I read your post a few times trying to let it sink in. My original curve for all fans was 0c to 60c at 40%, and 70c on at 100%. My CPU reaches 80 - 82c under heavy load. I know that's a little high but its an AM5 7700x chip at default 1.4v core voltage.
 
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Paperdoc

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That fan curve is probably OK. However, I note that the result is that the fan actually goes to 100% full speed around 80C, and your CPU runs just above that at heavy load. You could try to lower the temperature for max speed to 60 or 65C. That might lower its operating temperature at workloads a bit less than max.

Typical default fan curves pre-programmed into automatic control systems (using the "Normal" or "Standard" fan Profile option) tend to use a continuous curve of several steps from low to high temps, rather than the two-level "curve" you have chosen.

You might note this finer detail. Most fan systems (like yours) today appear to use a "feed-forward" strategy. That is, they PREDICT what fan speed (really, power setting) will be needed for a given measured temperature to keep the CPU from overheating. So in your case for example, your curve tells it to set the fan to 40% power at any temperature up to 60C. Technically it does not try to reduce the temperature once it hits 57C, it just lets it go wherever until the 60 C point happens. THEN it speeds up the fan. This is not quite the same as a common "feed-back" deviation control system that tries all the time to keep the temp at a particular target. But this strategy is built into your mobo (like most others today) - it is not a result of your choice of fan curve. Your choice is not about the basic strategy. It is merely choosing the points where the prediction is to be changed.
 
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ReveurGAM

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Sep 28, 2022
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That fan curve is probably OK. However, I note that the result is that the fan actually goes to 100% full speed around 80C, and your CPU runs just above that at heavy load. You could try to lower the temperature for max speed to 60 or 65C. That might lower its operating temperature at workloads a bit less than max.

Typical default fan curves pre-programmed into automatic control systems (using the "Normal" or "Standard" fan Profile option) tend to use a continuous curve of several steps from low to high temps, rather than the two-level "curve" you have chosen.

You might note this finer detail. Most fan systems (like yours) today appear to use a "feed-forward" strategy. That is, they PREDICT what fan speed (really, power setting) will be needed for a given measured temperature to keep the CPU from overheating. So in your case for example, your curve tells it to set the fan to 40% power at any temperature up to 60C. Technically it does not try to reduce the temperature once it hits 57C, it just lets it go wherever until the 60 C point happens. THEN it speeds up the fan. This is not quite the same as a common "feed-back" deviation control system that tries all the time to keep the temp at a particular target. But this strategy is built into your mobo (like most others today) - it is not a result of your choice of fan curve. Your choice is not about the basic strategy. It is merely choosing the points where the prediction is to be changed.
That's a great point. What is considered to be the temperature to keep a CPU under for best results, including longevity? My son and I have an i5-12600k and i7-12700k respectively.
 

Paperdoc

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A quick search says that both of those processors should work normally at about 55 C for max workload, and 60 to 65 C is common. The MAX temp for each is about 100 C - near that temp I expect the OS would throttle the CPU speed to prevent reaching such a limit.
 

ReveurGAM

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A quick search says that both of those processors should work normally at about 55 C for max workload, and 60 to 65 C is common. The MAX temp for each is about 100 C - near that temp I expect the OS would throttle the CPU speed to prevent reaching such a limit.
Right, so I would think that as long as I keep the temps at or below 70, we should be able to get really good lifespan, performance and durability out of them. Do you agree?

Now, I just have to figure out how to alter Cincinnati summers to make that happen! ;)
 

Paperdoc

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Agreed.

Fixing the weather is one of those things everyone talks about but never does. It's like they all lack a strong enough sense of personal drive! Some people claim that anything is possible if you just try hard enough!

I live further north than you, so the problem is slightly less. But last year when we replaced an old furnace, we added central A/C. Works wonderfully well! 'Course, we've been in this house for over 50 years before we got to that.
 
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ReveurGAM

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Agreed.

Fixing the weather is one of those things everyone talks about but never does. It's like they all lack a strong enough sense of personal drive! Some people claim that anything is possible if you just try hard enough!

I live further north than you, so the problem is slightly less. But last yeare when we replaced on old furnace, we added central A/C. Works wonderfully well! 'Course, we've been in this house for over 50 years before we got to that.
Absolutely understood. I'm from Milwaukee originally.

I really cannot comprehend why the weather warlocks haven't yet assembled to master the weather. It's quite baffling, especially since the world is about to be destroyed by the Vogons. Or so Dirk Gently told me.

My name, by the way, is Dent. Arthur Dent. As in I dented your fender with my bumper.
 

Karadjgne

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Apart from what paperdoc has already explained, there's also one other factor. You are using software. By doing so, there's am assumption that it's using the exact same addresses and interpreting the voltages present at that address the exact same way.

CoreTemp and HWInfo64 authors have historically worked very closely, if not with, amd and Intel engineers to get it right, so they actually do run the same algorithms that amd and Intel uses and are as accurate as it gets. Asus has not, does not, and there's no guarantee that they even read the same sensors, but most likely take fan responses from their own temp reading, which can easily be wrong by 10°C at any given point.

Use one or the other, software or bios, don't try to use or compare one to the other, it'll get confusing.