Linking Case Fans to GPU temps

[Fennario]

GPU was heat soaking my system because the case fans were not ramping as it warmed up. Wanted to share how I linked my case fans to GPU vs. CPU temp without resorting to resource hogging/conflicting software like iCue.

System is built around an Asus Hero motherboard and related BIOS (assume that most other manufacturers have similar functionalities as described). All fan, RGB, and AIO functionalities are now hardware coded and no longer need to run background widgets at start-up. RGB set to indicate AIO fluid temp on the waterblock and fans; GPU, VRAM, and VRM temps along the EVGA rainbow bar; and some bling on RAM and keyboard (GSkill, Corsair).

Hardware/Install
1. Purchase $6 T-Sensor from Amazon https://www.amazon.com/gp/product/B00CMR38LC?psc=1
2. Attach T-Sensor to designated motherboard header
3. Route cable and Insert probe of T-Sensor into fins of GPU heatsink

BIOS Adjustments
4. Change case fans' input sensor from CPU thermal to T-Sensor
5. Add 12 second ramp down for fans (basically hysteresis).
6. Adjust case fan curves to ramp based on T-Sensor readings

Software Adjustments
7. Hardware encode AIO and Keyboard RGB in iCue then disable programs on start-up.

 

[robt100]

I have been wondering if this is possible, my bodge-fix was to check CPU temps when gaming vs idle and adjust the fan curves accordingly.

When you say to plug it into the designated motherboard header, which header do you mean??

 

[Fennario]

Hopefully you have a specifically labeled 2-pin T-Sensor header on your mobo (check your schematic). It's on the bottom right(ish) of my Hero XIII - in Image 2 above you can just barely see the cable/header which is under the X of RTX on the GPU. I ran the cable through the basement grommet, up around the back of the case, and out through the grommet alongside the GPU.

The header is usually used for watercooling set-ups to monitor the fluid temp and adjust radiator fan speeds based on its readings. Site below has the plug based ones which are used to tie into liquid loops as well as the one I linked above.

Thermal Sensor Fittings for PC Water Cooling | TITAN RIG

Use Thermal Sensor Fittings to monitor the temperature in your water cooling loop. Shop from EKWB, Bitspower, XSPC and more

www.titanrig.com

 

[Deleted member 197115]

Nice, the only problem is high CPU load scenario without much of a GPU which is the only one controlling intake fan.
On the other hand most games load CPU along with GPU, may be slightly more aggressive curve for CPU temp based fan would suffice. That's what I set mine to.
If only it could read max of two sensors (CPU and GPU).

 

[Fennario]

Baseline fan speed + 360mm AIO is more than sufficient - CPU is unable to push the liquid past 32c on its own no matter what I throw at it. Only thing that can/used to throw the system out of balance is too much GPU heat getting sucked into the AIO.

Underlying issue is that my BIOS can directly access the CPU die temp, but not the GPU or AIO (to the degree I've been able to figure out). As such, the case fans would noisily spike for CPU transitory loads; but not to evacuate heat building up in the case, AIO, or otherwise recognize that such was occurring. The only other way to link them properly would have been through software running in the background such as iCue or SpeedFan which use system resources.

My case fans are 140mm Nocutas (3 front intake, one rear exhaust) and start off at 40%/1000rpm baseline (whisper/barely audible). 360mm AIO is top mounted for exhaust and has three ML120 fans ramping via iCue hardware encoding as mentioned in OP.

N.B. If worried about AIO/CPU temps then you can leave the topmost fan linked to CPU vs. T-Sensor and it will continue to ramp as before - only the bottom one(s) will boost alongside the GPU.

 

[mrexcitement71]

I have a water cooled i5-10600kf and air cooled RTX 3080 and a case with descent cooling and wanted to do basically the same thing.
The corsair CPU cooler and software takes care of itself , I have it's radiator sucking in cool air from outside and exhausting into the case with the plan of removing this heat with good case cooling so what I did was use the ASUS motherboard fan software and tie all case fans to the motherboard temperature with a scale of 20c or less (min fan speed) to 30c and above (max fan speed), the theory being that the motherboard temperature will increase with the extra heat dumped into the case by the GPU and CPU then this in turn will increase the case fans.
It works very very well , the fans are only speeding up when they are actually needed whether it be GPU or CPU load or both.
It's quiet most of the time with the fans only speeding up after a bit of gaming and returning to normal a little bit after you finish gaming.

 

[Fennario]

Makes sense. Critical difference in your set-up is the AIO is set for intake which protects your CPU from GPU heat at the expense of slightly higher GPU temps (AIO increases the temp of intake air compared to ambient). I wanted to give the GPU as much headroom as possible so reversed the equation which disadvantages my CPU due to AIO sucking in air heated by the GPU. As such, felt it was best to minimize the build-up by linking directly to the GPU heatsink vs. waiting for the motherboard to soak a bit.

 

[Deleted member 197115]

GPU always runs hotter than CPU, as I have both on AIO, CPU cools on intake and GPU on exhaust.
Ideally both needs to cool off intake but that would require some special case.

 

[Fennario]

I think that the heat output of the 3090 will push me to a full liquid loop at some point. Only way to get the thermals I am looking for. Just don't want to spend the time/money/risk at this point tearing a new system apart. Will probably wait for the eventual 13900k in a year or two before doing the upgrade. Real world impact from going custom loop would be aesthetics/quieter system and not dramatic performance increases.