Question CPU reaches 95temp but my fans wont work at full speed

Dejoboss

Prominent
Apr 19, 2024
11
1
515
Hi guys,

I scanned my PC with Windows security and my CPU reached temperature of 95/97 degrees. i turned on fan boost and managed to lower the temp on 80.
The problem i managed to see is that my fans dont follow the scheme. On any temp above the 80 my fans were supposed to work on full speed.
I tried to do it manually through the bios but nothings changed. the temp still reaches up to 95 and my fans are working like its 60.

Also my idle temp is around 40/50 degrees but when i open anything it knows to jump over 70 for a short period. Games are constantly around 70/75.
My CPU is Ryzen 9 7900x
Liquid cooling COOLERMASTER MLW-D36M-A18PZ-R1
 
Welcome to the forums, newcomer!

How is the AIO mounted in your case? Make and model of your case? Ambient room air temps? Make and model of your motherboard? BIOS version for your motherboard?
AIO is mounted on top of the case with airflow from inside out. Case model is COOLERMASTER MASTERBOX 540.
Motherboard is Gygabite Z790 GAMING X AX.
And i instaled latest version of BIOS 2 when i built my PC 2 months ago.
 
Exactly which fan header have you used to plug in the PUMP cable? Did you configure that header to use Normal Fan Speed Control, and PWM Mode?

Same questions for the header where you plugged in your rad fans, PLUS which Temperature Input did you choose for those fans?
 
Well, I'm going to admit I feel a bit clueless right now.

When I think back, I realize that I didn't even pay attention to the details of which header to plug the fan into. I'll have to check it out. Can you assist me with the header configuration? How do I do it? Is it through the BIOS, or is there a specific program for that?
I'm not too much of an expert, so I was just guided by the theory that the air circulates properly through the PC case. 🤦‍♂️
Exactly which fan header have you used to plug in the PUMP cable? Did you configure that header to use Normal Fan Speed Control, and PWM Mode?

Same questions for the header where you plugged in your rad fans, PLUS which Temperature Input did you choose for those fans?
 
Yes we can advise. There are two major factors, and several little details. I'll concentrate on your AIO cooler system, and om you mobo.

If you don't have them, the manuals are here

https://coolermaster.egnyte.com/dl/cGaeJhIVy8

and

https://download.gigabyte.com/FileL...e_1201.pdf?v=785f17b03d67c74868bc0a408afe237b

Details of how to use BIOS Setup for that board are in this manual

https://download.gigabyte.com/FileL...bios_e.pdf?v=aceb9fb3f69cc73ea6b2fddd6a6f34ed

Your AIO system has one pump unit and three fans. Each of those has TWO cables. One ends in a smaller fan motor header connector, and the other ends in a wider ARGB lighting connector. On the PUMP, the MOTOR connector has only three holes, whereas on each actual fan the FAN motor connector has FOUR holes. For both units, the wider ARGB LIGHTING connector has 3 holes, but looks like it had 4 and the third one is blocked off. Most of this is dealing with the MOTOR connectors.

For the AIO system you are best to use two connectors beside each other at the top above the RAM slots - see the manual p. 4, 18 and 20. Plug the 3-hole smaller motor connector from the PUMP into the CPU_FAN header - Item # 3 in the p. 18 diagram. To use the three rad fans, use the Splitter supplied with your AIO system - see its manual p. 2, Item M, and p. 17 - and plug the female 4-hole input end of the Splitter into the mobo CPU_OPT header, Item 6 on p. 18. For now, ignore the LIGHTING cables from each of those items until the AIO cooler is working.

Next you will need to go into BIOS Setup to make adjustments to the CPU_FAN and CPU_OPT headers. See the BIOS SETUP manual p.2 to get started. When yo push the Power button, immediately HOLD DOWN the "Del" key on the keyboard (do not just tap it) until the opening screen appears (p. 3). You MAY need to tap Del once more to get to the Main Menu (p.4). Use F6 to get to the Smart Fan 6 Screens (p. 6). At upper left of this screen you can choose exactly which fan header you are working on. At upper right you can make adjustments for that one header. When all is done you can exit out to save your new settings.

Start by choosing the CPU_FAN header. At upper right, make these settings:
CPU_FAN speed Control to Normal
Fan Control Use Temperature Input to CPU
Temperature Interval probably OK as it is (3?)
CPU_FAN Control Mode to PWM, not to Auto or Voltage
CPU_FAN Stop to DISabled so you Pump never stops
Fan Mode to Slope
Fan Fail Warning to ENabled so you WILL get a warning if the pump ever fails

Now choose the CPU_OPT header and make the SAME settings as above for that header. You can save this set of settings in a named profile if you wish, but that is not necessary. NOTE that there are many other items that can be adjusted in BIOS Setup, and we have only worked on those two headers involved in CPU cooling.

Now use the Esc key just to return to Main Menu, then F10 to get to the Exit Menu (p. 29). There choose Save and Exit to save these settings and reboot.

With this arrangement of your AIO system, the PUMP should run at full speed all the time as intended, and its speed signal will be monitored for failure as indicated by NO speed. If that ever happens you will get a prominent warning on-screen, followed shortly thereafter by a complete shut-down of your system to prevent CPU overheating damage. Meanwhile the three RAD FANS connected to the CPU_OPT header will all run the same way under automatic speed control according to the temperature as measured by a sensor inside the CPU chip. Because they all are connected to one header, that header can monitor the speed of only ONE of those fans and show the result to you. From time to time YOU should look at those three fans and be sure they all still are operating.

The reason I asked for the connection detail is that manuals for these systems do NOT tell you that many AIO and mobo combinations will have the PUMP run at too slow a speed and that significantly reduces the ability of the system to cool the CPU. That may be what caused your problems at high workloads. The key item here is setting the header where the pump is connected to use the newer PWM Mode to ensure the pump is always fed a full 12 VDC power supply.

IF you have any issues with the CASE VENTILATION fans, they all should be connected to the mobo SYS_FAN1 to 3 headers. IF you have to use SYS_FAN4 for a fan, make sure in the configuration of that header (BIOS Setup Screen p. 6) that it is set to be a FAN header, not a PUMP header. Otherwise set them up the same as above for the CPU_FAN EXCEPT for these two items:
1. Fan Control Use Temperature Input to Motherboard, not CPU; and,
2. SYS_FAN Control Mode to PWM if your fans are 4-pin PWM style, OR to Voltage or DC Mode if your fans are older 3-pin type.

You have not asked about the LIGHTS in these items, but here are some tips. Your mobo has two sets of headers for lights - one pair at top front, and another pair at bottom near the back. At each location there are two DIFFERENT headers. For the 3-pin ARGB LIGHTS in your AIO system components you must use the headers marked DLED1 and 2 - see the mobo manual p 21, Item 7. These each have THREE pins that look like there were 4 and Pin 3 is missing. Do NOT try to use the 4-pin LED/C1 and C2 headers (p. 22, Item 8) - the are only for a different system called plain RGB. Your AIO system came with an ARGB Splitter cable - see its manual p. 2 Item O and p.17. You plug the LIGHTING cable from each fan AND the one from the PUMP into male output connectors of this Splitter, and then the female Input connector goes to ONE of those DLED1 headers, You might want to wrap the pins of the fifth unused output with tape so they do not short out by accident.

If you have ARGB lights also in your case vent fan frames, you can use another ARGB Splitter if necessary to connect them to the other DLED2 header. IF your case vent fans have the other lighting type (4-pin plain RGB) you would use the 4-pin LED/C1 header for them.

Adjustment of lighting dsiplays is not done in BIOS Setup. For that you use the utility supplied with the mobo on its optical disk, Gigabyte Control Centre. Elsewhere in that same software app you probably will find ways to adjust the fan headers, too, without using BIOS Setup, if you so desire.
 
Last edited:
Dude, thank you for this big explanation. You are a hero.

I checked fan connectors and saw that my 3 fans from AIO were not connected on CPU_OPT but on SYS_FAN1. Reconnected them and now my fans are following instructions properly. My temp is a lot better but still have small issues. I think those are because my front fans (140) are to big and half of the fans are covered with a metal part from a case. Since there is no option to make them fit better i will have to buy 3 new smaller ones (120). Tomorrow i will play a little with BIOS settings. Also just in case, i changed a thermal paste on my CPU.

This is huge help and i really appreciate it.