3-Pin Fan Connectors, 4-Pin Mobo Connectors, Chassis Fan Controller? Help?

[jseymour]

Hi There,

The things They Do Not Tell You

Fractal Design Define R4 Black Pearl case. Asus Z87-A mobo.

I have:

1. The two chassis fans
2. Two 3-pin female connectors on chassis cables
3. Two 2-pin connectors on chassis cables with which the 3-pin connectors in (2) appear to mate
4. Three 4-pin male fan connectors on the mobo, which appear to be keyed such that the 3-pin connectors in (2) appear to mate correctly

Using the SWAG method, I'm guessing that 2 + 3 = fans controlled by the case's fan controller, and 2 + 4 = fans controlled by the mobo.

I'm going to further guess that the mobo will moderate the fan speed based on thermal load, but the case's fan controller...?

Lastly: I'm guessing having the mobo control fan speed: I'll be able to read/monitor fan speed with the O/S, whereas, with the chassis controller: Not.

How did I do?

Thanks,
Jim

 

[kyij]

I just looked up your case and watched neweggs video to familiarize myself with it..

Firstly, a few things: all motherboards will have fan connectors. A majority of fans only have 2/3 pins - but they will all use a 3/4 pin connector (unless they are molex). A motherboard will typically have only 3 pin connectors (except for the cpu cooler).

Normally people just plug there fans into their mobo's, unless they want to use a speed controller/have too many fans/etc.

Except your case has a fan controller built in. It lets you adjust from 5/7/12 volts. So to use these features, your fans need to be connected to the cases controller (the cases 3 pin connectors). To power the two fans connected to this controller, you need to power the controller via the molex connector. You just use one of the molex cables from your power supply.

You do not need to use the case's controller, but if you want to be silent - you can readily change it to 5v, and switch to 12v if your doing more processing power / need to cool down your computer some. Otherwise you can just connect the fans to the motherboard's connector..

2 pin connectors on the chassis? Typically those are for power/reset, unless I am mistaking what your talking about.

Anyone feel please to add more if you think it will help or if I missed/messed something up.

 

[doyll]

Fan pin-out on pins 1 & 2 is the same on all normal fans. Pins 3 & 4 as below.
Pin 1 = Grd
Pin 2 = 12v (variable voltage for speed control)
Pin 3 = Sensor (rpm signal from fan)
Pin 4 = PWM (PWM signal to fan for speed control)
Image shows 2, 3 & 4 pin fan as well as molex

Motherboard headers are 2, 3 & 4 pin. Often chassis fan headers are now 4 pin, but only the 4 pin CPU fan headers are PWM. The others are not PWM!!
Images show 3 pin & 4 pin headers.

4 pin plug can be used on 3 pin & 4 pin headers.
3 pin plug can be used on 3 pin & 4 pin headers.

I have found the stock Define R4 fans (R2 fan) to be lacking in airflow. Changing them to a better 140mm PWM fans and using a PWM splitter with PSU power allows the case fans to use CPU fan header PWM signal to control them. This allows both case and CPU cooler fans to change speed / airflow as needed to supply airflow for cooling.. thus making system much quieter when system is not working hard. This can also be done with GPU PWM fan signal to control the case fans supplying GPU airflow. If you need more info just ask.

 

[jseymour]

Thanks for the feedback, guys.

I'd already gone ahead and plugged them into the mobo. According to the BIOS they're running at a bit over 600 RPM. They're so quiet that I actually had to look at them to tell if they were running. Later on I'm going to hit the system with something CPU-intensive to see how they react.

As an aside: The 120mm cooler (Noctua NH-U12S) fan runs so slow I had to turn the BIOS CPU fan speed alarm threshold down from 600 RPM to 300. (The CPU, Intel i5 4570S, is idling at 30°C.)

The PSU fan is, likewise, so quiet you cannot hear it running--at least at idle.

The exhaust temperature is actually cool to the feel.

Jim

 

[doyll]

Keep an eye on motherboard temps. Sometimes when fan speeds get very low mobo components heat up.. not enough airflow over them.

 

[jseymour]

Keep an eye on motherboard temps. Sometimes when fan speeds get very low mobo components heat up.. not enough airflow over them.

So far I've only been able to get "Temp 1" and "Temp 2" (don't know what they are), which are 28°C and 30°C, respectively, and the four CPU core temps. The latter range from 24°C to 26°C when the system's mostly idle, to a high of 42°C to 47°C with all four cores running at 100%. (The high limit is 86°C and critical 92°C.) "Temp 1" and "Temp 2" have so far never changed.

When it's running with all four cores at 100% for a while, the exhaust air eventually becomes... I wouldn't call it "warm," per se, but no longer cool. The fans never did get noisy, even with that test running for... a half-hour or so? I think I may have heard the CPU cooler fan speed up.

I did some research on the board last night. It seems I have to install a new kernel module in order to see more mobo information.

Jim

 

[doyll]

With those temps you don't have anything to worry about.