Question Rear case fan slow/stops spinning, while GPU fans are spinning okay ?

[p.heats]

Please help, im use Deepcool Matrexx 50 case have 3 front case fans and 1 rear case fan. It was working normally before, then when i upgraded my GTX 1050 to an RTX 3060 I have problem: When I play a game longtime (Monster Hunter, Diablo 4,..) the RTX 3060 fans are spinning (i know that's normal) but my rear case fan spins slower over time, then if im playing a long time (3 hours+) it stops spinning (not fully stopped but spins jerky). My PSU is 700W and CPU i5-11400f (1 CPU cooler fan) please help me, I don't know what happened or if I need to buy new rear case fan?

 

[CountMike]

Please help, im use Deepcool Matrexx 50 case have 3 front case fans and 1 rear case fan. It was working normally before, then when i upgraded my GTX 1050 to an RTX 3060 I have problem: When I play a game longtime (Monster Hunter, Diablo 4,..) the RTX 3060 fans are spinning (i know that's normal) but my rear case fan spins slower over time, then if im playing a long time (3 hours+) it stops spinning (not fully stopped but spins jerky). My PSU is 700W and CPU i5-11400f (1 CPU cooler fan) please help me, I don't know what happened or if I need to buy new rear case fan?

GPU fans are controlled by GPU, no connection to case fans or BIOS. Speaking of BIOS, check settings and speed curve for that rear case fan and maybe let it spin faster.

 

[Paperdoc]

Please tell us WHICH mobo fan headers you have used to plug in the REAR fan and the FRONT fans. PLUS, tell us exactly what maker and model is your mobo? What you describe may be simply how your fan curves are set. With the info requested we can look up details and offer more precise advice.

 

[p.heats]

Please tell us WHICH mobo fan headers you have used to plug in the REAR fan and the FRONT fans. PLUS, tell us exactly what maker and model is your mobo? What you describe may be simply how your fan curves are set. With the info requested we can look up details and offer more precise advice.

im using Gigabyte B560 AORUS pro v1.0

before this rear fan work normally (still while im play diablo 4, monster hunter...) then when i upgrade from GTX1050ti (1fan) to RTX3060(3fans), while play game then RTX fans spinning -> rear fan slowdown -> jerky. Please help if i can setting in BIOS (I'm not good at editing BIOS) thank you.

 

[p.heats]

GPU fans are controlled by GPU, no connection to case fans or BIOS. Speaking of BIOS, check settings and speed curve for that rear case fan and maybe let it spin faster.

ahhh thank you, before I'm worried GPU fans spinning make my rear fan slow.

 

[CountMike]

im using Gigabyte B560 AORUS pro v1.0

before this rear fan work normally (still while im play diablo 4, monster hunter...) then when i upgrade from GTX1050ti (1fan) to RTX3060(3fans), while play game then RTX fans spinning -> rear fan slowdown -> jerky. Please help if i can setting in BIOS (I'm not good at editing BIOS) thank you.

There should be settings in BIOS to regulate each fan header on the MB. It's either something like Low-medium-High or speed curve adjusting. Idea is to make lowest speed higher. Should be able to find those in MB manual.

 

[helpstar]

maybe the GPU is cooling the motherboard´s temp. sensor and the rear fan doesn´t have to spin that much anymore

 

[Paperdoc]

Helpstar and CountMike above have given you great ideas. Maybe this can help you with the details. Helpstar's comment may explain why the fan now is trying to run slower and that causes it to stall sometimes. CountMike points to how to fix that.

Go into BIOS Setup (p. 25 of your manual). Use the F6 key to get to the SmartFan screens (p. 26), choose the particular CHA_FAN header where you have that rear fan plugged in, then make these settings using the drop-down choosers at upper right.
1. CHA_FAN Speed Control to Normal.
2. Fan Control Use Temperature Input to Motherboard
3. CHA_Fan Control MODE to Voltage IF that fan has 3 wires and pins in its connector, OR to PWM if the fan is a 4-pin type
4. CHA_FAN Stop to DISabled so it never stops
5. Fan Fail Warning to ENabled so you do get a warning on-screen if the fan stops

By the way, those same settings should be used also for the other CHA_FAN header where you have your three front fans plugged in.

Use the Esc key back to the Main Menu, then F10 to get to the Exit Menu (p. 43)
There choose Save & Exit Setup to save your settings and reboot. See if that makes a difference.

If this still allows your rear fan to stall, go back into BIOS Setup, select that fan header, and make this adjustment. First, note that graph of fan speed versus temperature. Now change the CHA_FAN Speed Control to Manual so you can set your own version of the fan curve. In the table of values across the bottom make it the same as it was in the original "Normal" Profile. Then for the first (lowest temp) point on the graph change the PWM value to something a bit higher, like 30%. This will ensure that the fan at its slowest speed never goes slower than that setting. That should prevent it from stalling at the coolest temperature. Again, use the Exit Menu to Save & Exit Setup.

 

[p.heats]

Helpstar and CountMike above have given you great ideas. Maybe this can help you with the details. Helpstar's comment may explain why the fan now is trying to run slower and that causes it to stall sometimes. CountMike points to how to fix that.

Go into BIOS Setup (p. 25 of your manual). Use the F6 key to get to the SmartFan screens (p. 26), choose the particular CHA_FAN header where you have that rear fan plugged in, then make these settings using the drop-down choosers at upper right.
1. CHA_FAN Speed Control to Normal.
2. Fan Control Use Temperature Input to Motherboard
3. CHA_Fan Control MODE to Voltage IF that fan has 3 wires and pins in its connector, OR to PWM if the fan is a 4-pin type
4. CHA_FAN Stop to DISabled so it never stops
5. Fan Fail Warning to ENabled so you do get a warning on-screen if the fan stops

By the way, those same settings should be used also for the other CHA_FAN header where you have your three front fans plugged in.

Use the Esc key back to the Main Menu, then F10 to get to the Exit Menu (p. 43)
There choose Save & Exit Setup to save your settings and reboot. See if that makes a difference.

If this still allows your rear fan to stall, go back into BIOS Setup, select that fan header, and make this adjustment. First, note that graph of fan speed versus temperature. Now change the CHA_FAN Speed Control to Manual so you can set your own version of the fan curve. In the table of values across the bottom make it the same as it was in the original "Normal" Profile. Then for the first (lowest temp) point on the graph change the PWM value to something a bit higher, like 30%. This will ensure that the fan at its slowest speed never goes slower than that setting. That should prevent it from stalling at the coolest temperature. Again, use the Exit Menu to Save & Exit Setup.

thank you i will follow your step hope it can solve my issue.