Adjusting the fan speed

Hi. I have an MS 1763 with the GTX 870M equipped. Have it for three years.

The fan of this notebook has always been noisy. But since now it is winter, it is not as noisy as before due to low temps. I've also changed thermal paste of the GPU and cleaned the fan and such and as result, temperature of the GPU doesn't go over 80c. But the fan becomes too noisy as soon as the GPU temp reaches to 75C.

I've checked the fan speed at this temperature via MSI GT70 Fan Control program and it is at %50. So since I find that speed too noisy I lowered it down to %40 and it is perfectly acceptable to me in games. But the problem is, the fan stays at %40 speed as long as it doesn't reach to 75c but as soon as it reaches it adjusts speed to %50 again.

Now I get why it does that, to lower temp but I just wanted to try and see how temps are doing at %40 fan speed above 75c. It doesn't let me.

So I ask, how can I lock the fan speed at %40 all the time? I monitor temps via MSI Afterburner in games so if temps go nuts I will revert it. It is not like the GPU is gonna burn anyway. Thanks in advance.

 

There usually is a fairly involved strapping table in the BIOS that looks at many of the temperature sensors and sets when speeds are adjusted upwards or downwards. Most manufacturers will tweak this a little depending upon the type of cooling system they put in (type of fans, their airflow in CFM, back-pressure, noise, heat-sink efficiency). Most of the folks are not engineers who are going to do all of the math to come up with the settings, they will get close by using default values and then tweak them a little. That tweaking will depend upon how close to the edge of operation they want to be, system noise (often ends up being driven by marketing types who say "why does it have to be so noisy?").

What they usually get wrong are the steps upwards and downwards. There is a "deadband" of the values where once a temperature is attained, the fans will continue at that speed until the temperature moves by a certain number of degrees C one way or the other. This is called "hysteresis" and is meant to minimize the hunting behavior if the temperature was to sit right at 50 C when the control point up and down was 50 C (the fast-slow-fast-slow changes would make you nuts).

What almost never happens is the rework that really is needed when some parts supplier comes along six months later and has a slight change in the fan they supply, the heat sink compound they are using, processor speed tweaks or heat sink manufacturing technique (milled heat sinks perform differently than extruded heat sinks even if they have exactly the same physical dimensions).

Most fan controllers take pulses from the fan to report back the spinning speed and can use one of several different techniques to drive the fan (PWM, pulse width modulation) or maybe even just a simple stepped voltage control (very old school). These same people do not understand that if you make a fan 20% slower it does not mean that it cools 20% less, the relationship between speed, fan design, CFM and heat removal is much more complicated than that.

You would either need to access the strapping tables (or even a mathematical formula that figures out these control points) and to make your own changes. The disadvantage is that you are going to be making the changes in total ignorance of what they had already gone through to get to where they are right now. (ignorance is not an insult, it just means that you do not know). You would have to go through quite a bit of trial-and-error to come up with your own fan steps and it is just as likely that it will be no better than what they had already chosen (no, I do not believe that father knows best and should never be challenged, just that it is much more complicated than people think).

The other thing you could do is to "fake it all out" and just bypass the fan control and the temperature sensors and to put your own little controller in there (like a linear controller using something like an op-amp and a voltage regulator or a little PWM source, all controlled by a potentiometer).

 

Thank you for the detailed answer! I was thinking it is going to be difficult too but I just found a program that does exactly what I want!

https://www.techinferno.com/index.p...w-to-control-fan-for-g-series-laptops/&page=1

I don't know how Pherein (the person who did this program, many thanks him/her) have achieved doing this so perfectly. Maybe it has to do with something you mentioned about "fake it all out" but it is exactly working as intended. Surprised, it is fairly easy to do!

By following the instructions in the Techinferno forum topic I managed to get it working. I just set the fan speed at %40 for the all temp tables and executed. The result: the fan speed always stays at %40, no more up and downs! Even if the GPU temp reaches over 75C it still stays at the same spinning speed, amazing. The GPU temperature doesn't go over 82C too! Perfectly acceptable. I could even overclock the GPU haha. I'm sure if I look on those temp tables and fan speed in the program more it will only get better with a little try and see method. I'm happy some peace at last regarding to noise, at least until summer lol, then we will see how temps will do at this fan speed.