What wrong with my cpu fan header?

[lamdnhan]

Greeting,

 

I'm having problem controlling fan speed.

 

My mobo is Asus Z97i-Plus, i5 4690k cooled with seidon 120M.

 

The problem is that the radiator fan does not perform as it should. I manually changed the fan speed to 100% when CPU reach 60*C.

 

When the temp start to reach 60*C, the ran does ramp up to around 80% then slowly drops back to around 60%. It's connected to the CPU Fan Header on the motherboard, if I connect it to Chasis 1/2, it perform normally.

 

Here's the images:

If connect to CPU fan header: https://imgur.com/SVTTPr5

If connect to other 2 headers: https://imgur.com/psZl1vb

 

I suspect Asus AI suite causes the problem, but uninstalling it has no effect.

 

What should I do? :wacko:

[ZetZet]

Does it go over 60?

[lamdnhan]

Does it go over 60?

Yes, running a quick benchmark make it reach around 65*C

[LogicalDrm]

There are some weird readings. The maximum rpm of that fan is 2400. So the pic of CPU fan header is reading correctly between the control graph and rpm related to that. On other pic you have selected wrong control reading. It should be using Fan2 instead. I'm not sure how well % readings from OHM relate to rpms. Have you use that software side by side with AI Suite? That could help to determinate where problem is, if there is one.

 

Is your pump connected to mobo CPU_FAN header too? Does it have some profile applied or is it set to run at full speed all the time? Because CPU_FAN and CPU_OPT are same header, they are controlled by same chip on mobo. So anything connected to secondary header will run at same speed with primary header.

[lamdnhan]

There are some weird readings. The maximum rpm of that fan is 2400. So the pic of CPU fan header is reading correctly between the control graph and rpm related to that. On other pic you have selected wrong control reading. It should be using Fan2 instead. I'm not sure how well % readings from OHM relate to rpms. Have you use that software side by side with AI Suite? That could help to determinate where problem is, if there is one.

 

Is your pump connected to mobo CPU_FAN header too? Does it have some profile applied or is it set to run at full speed all the time? Because CPU_FAN and CPU_OPT are same header, they are controlled by same chip on mobo. So anything connected to secondary header will run at same speed with primary header.

 

I believe not.

 

Basically I switched the header and run a quick benchmark. First, Rad fan connected to CPU header , pump on chassis header. Second, pump on CPU header - set at full speed, rad fan on chassis header.

 

I think the result should be something similar to the one I connect it to chassis header, which responses to temp correctly and does not drop rpm/%

 

My BIOS can control 3 fans separately, and I don't use any fan splitter so it may not the case.

[LogicalDrm]

I believe not.

 

Basically I switched the header and run a quick benchmark. First, Rad fan connected to CPU header , pump on chassis header. Second, pump on CPU header - set at full speed, rad fan on chassis header.

 

I think the result should be something similar to the one I connect it to chassis header, which responses to temp correctly and does not drop rpm/%

 

My BIOS can control 3 fans separately, and I don't use any fan splitter so it may not the case.

 

Have you tried with pump on single header at all time and not switching them both around? Sounds to me like there's too many variables to check if it is A. BIOS issue B. Software issue or C. header powering issue. Because for me it it really weird that header can power pump to full speed and choke on fan. They use same 12V max (1A). Fan should be using less than the max 1A, don't know about pump.

[lamdnhan]

Have you tried with pump on single header at all time and not switching them both around? Sounds to me like there's too many variables to check if it is A. BIOS issue B. Software issue or C. header powering issue. Because for me it it really weird that header can power pump to full speed and choke on fan. They use same 12V max (1A). Fan should be using less than the max 1A, don't know about pump.

 

I'll do another test run and post the result later. This time the pump will be powered by molex to make it less confusing. 

 

1. BIOS issue - Probably, but for all the versions of BIOS I've installed, they all have the same behavior

2. Software issue - I don't have any fan control software installed. Asus AI Suite does have some kind of fan control, but I don't find much use and ended up uninstalled it. The fan is now set by BIOS

3. Header issue - This is what I suspect, the CPU fan header ramp the fan up around 80-90% then quickly slow down below 60% and jumps around that range. It's supposed to be stable and response to CPU temp set by BIOS.

[LogicalDrm]

I'll do another test run and post the result later. This time the pump will be powered by molex to make it less confusing. 

 

1. BIOS issue - Probably, but for all the versions of BIOS I've installed, they all have the same behavior

2. Software issue - I don't have any fan control software installed. Asus AI Suite does have some kind of fan control, but I don't find much use and ended up uninstalled it. The fan is now set by BIOS

3. Header issue - This is what I suspect, the CPU fan header ramp the fan up around 80-90% then quickly slow down below 60% and jumps around that range. It's supposed to be stable and response to CPU temp set by BIOS.

 

Ok. So the way BIOS controls it has something wrong. Like too tight curve. If you have set the limit to 60C and temp drop under it during the time of testing/load, then the speed would also make drops. Thats about all I can help with this. Whatever it ends up to be (like AI Suite haunting in BIOS settings), I doubt you can RMA it because of such small issue.