CPU fan 2 at constant speed - cant determine fan location

[Mattbodom]

I am new to PC gaming so please bare with me. I have the NZXT Phantom 630 case and there are 2 NZXT fans on the top of the case, 1 intake fan at the front and 1 angled sort of facing the motherboard/graphics card. I am also running a 'Cooler master 120v V2" CPU cooler. When i open MSI command centre, i am able to change the speed for CPU fan1 and also 'system fan' The CPU fan2 does not respond to any changes i make in the software. I followed the wire and it is plugged into 'cpu2' on the motherboard, the actual fan seems to sit behind the CPU cooler master fan. As for the 2 fans on the top, the one facing the graphics card and the intake fan, they all respond to the fan control on the actual case. My question is why does the system fan respond to the software and also the case buttons, it seems like the only one that is controlled fully by msi command is the Cooler master CPU cooler :/ So in total there are 6 fans, 4 of which are controlled by the case, and 2 can be controlled in the MSI Command centre, that means that the 'system fan' must also be a case fan. I want to run an efficient cool system, a balance between noise, good temps and performance. Any help would be appreciated, i dont really want to start messing around with the wires etc if its unneccesary. Thanks again

 

[Paperdoc]

The NZXT case came with four fans pre-installed and connected to the case's own control system. That consists of buttons on the case top front to set all those fans together to either Low, Medium or High speeds. The mobo has no control over those fans, cannot display their speeds, and does not even know they exist.

I don't understand what "system fan" you have. Your Cooler Master liquid cooling system for the CPU has one fan attached to its radiator. You don't mention any others.

The Cooler Master cooling system does have two connections to mobo fan headers. The cooler's manual does not make it very clear how these should be done, but I can guess. One of its two leads comes directly from the fan on the radiator and has 4 holes (it's a female 4-pin fan connector) and should go to the mobo CPU_FAN1 header. That would allow the mobo to control the fan's speed and check it to be sure it is running. The other lead comes from the pump unit and has only 3 holes in it, and that should go to the CPU_FAN2 header. This means that the connection to the pump acts like a 3-pin fan. Plugged into a 4-pin standard fan header that uses PWM Mode (as most CPU_FAN headers do by default), that pump unit can only operate at full speed all the time. This is because of the difference between the designs of 3- and 4-pin fan types. But that is just fine for this purpose - you WANT your CPU cooling systems PUMP to run full speed all the time. The control of CPU temperature is done by changing the FAN speed on the radiator, not by changing the pump speed. So, although you may try to change the speed of the device (the pump) connected to CPU_FAN2, the pump itself cannot respond to the PWM signal it is being sent, and it won't change its speed.

That is why I asked where is this "system fan". If what you mean is that you do not have six actual fans, but you have something on the CPU_FAN2 header that does not change speeds, that is what you should observe. On the other hand, if you DO have a sixth fan, where is it plugged in? And, where is the pump unit plugged in? Also, post the exact model number of your MSI mobo so I can look up its manual for more complete info.

 

[Mattbodom]

Hi i am looking now and there is a fan behind the coolermaster, with rgb lights around it, that is connected to CPU fan 2. Also it is CPU fan2 that wont change speed. The coolermaster is connected to CPUFAN1, the multicoloured fan is connected to CPUFAN 2 and the wire that comes of the square black bit that sits on the CPU is connected to system fan2. Now this has allowed me to change the speed previously. Does this mean i need to have sysfan2 on 100% (connected to tge pump) all the time? I have had no problems in terms of heat etc

Thanks for your help so far, im very new to all this p.s my mobo is the MSI z97a gaming 7

P.s p.s Afyer reading your first comment again, should i basically swap around the cpu2 and system. I assume the current cpu2 fan is the exhaust fan so it would make sense that i can change that, but not the pump. Waiting to find out what you think before i do it though

 

[Paperdoc]

Yes, I would advise changing. Plug your pump unit's 3-pin connector into the CPU_FAN2 header, and plug your lighted sixth fan into the SYS_FAN1 header. That will put the sixth fan, which is for case ventilation, under control based on the mobo temperature. There are two other SYS_FAN headers that are NOT in use, and so of course they will not show any fan speeds or make and changes.

 

[Mattbodom]

Thankyou for your help, i do actually have a strip of lighting connected to sysfan2 but i can easily do the swap still, thanks again

 

[Paperdoc]

You're welcome, and thanks for Best Solution.

 

[Mattbodom]

No problem