So, I just verified I have a 4 pin case fan! Now how the heck do I use PWM? Pwease?
What if I have the luck of a black cat under a ladder..Aha! COLGeek has found the big clue! In the photos in OP's other thread the RED header has 4 pins but it is NOT a standard 4-pin fan header. So what its pins do, and whether or not it even uses the new PWM method of fan control, is totally unknown. I can say you can NOT plug any standard 4-pin fan in there. The red plastic "tongue" sticking up beside the pins covers the FULL width of the header, whereas the standard "tongue" covers only the width of Pins 1 to 3.
The nearby three-pin header in white appears to have a label on it that says "FAN3", so it MAY be a standard 3-pin header. BUT we cannot know that for sure, considering that the 4-pin header is NOT standard.
Bottom line: IF the white 3-pin header really is a standard fan header, then you CAN plug in there the connector for a 4-pin PWM fan. There simply will not be any pin for the 4th hole in the connector, but the ridges in the connector side should fit around the white "tongue". IF you're lucky, and that header is standard 3-pin, the fan will run and have its speed controlled as if it were a 3-pin fan, but not using the new PWM control signal system.
First of all, I haven't tried plugging in my existing fan (the one that is perfectly aligned with the strange RED 4 pin header) in the 3 pin header because I figured it wouldn't physically plug in, but now that I think about it (actually think about it) I think it would work!! (try that later though I'm super tired right now) Second, my existing fan used to change speeds (because it would literally be so LOUD when I'm playing a heavy game) but now after I unplugged it to see the header and then plugged it in again, it doesn't do that any more. It's just stuck on one speed (not the highest speed btw because it's very quiet) Why?If the fan does work, and MAYBE if its speed also changes as your worload varies, then you ARE lucky. If it does not run when you try it there, unplug, because we have no way of verifying what that header is doing.
Thanks for Best Solution.
What exactly is the OLD Voltage Control Mode? Is it changing speeds of the fan according to the workload? And how do I make the 3 UNKNOWNS, known? Also, there is a misunderstanding. My existing fan is a FOUR pin fan! (The one that I said was running at constant slow and quiet speed. I have no idea if it's a PWM fan or not though) And it's plugged in the RED 4 pin header. The WHITE 3 pin header is not being used at all right now. My case only has only ONE place to put a fan in it anyways.I don't recommend plugging the 4-pin fan you have (formerly on the red 4-pin header) into the 3-pin header. We have no way of knowing what the connections on all the pins are. And why? If I understand you original query, having just realized that the fan has FOUR pins on the red header, you assumed it must be a PWM-style fans and want to know how to make use of that. Well, it MAY be PWM, maybe not, but if it IS and was included with the mobo, the I would bet it ALREADY is being used as a PWM-stype fan. The main difference in that newer design (compared to 3-pin older fans) is a change in the electrical METHOD of controlling its speed, but NO change in the fact that is speed IS controlled according to a temperature measured on the mobo. The PWM method has slight technical advantages, but you would not notice them normally without careful experimentation. Now, IF that fan with 4 pins is really a PWM design and IF the pinout on its connector is "standard" and IF the white 3-pin header really is a standard 3-pin one, then that white header can NOT make any use of the PWM Method. IF all of those unknowns are true, plugging the 4-pin fan in there would would control it via the OLD Voltage Control Mode, and NOT make any use of the PWM feature!
As to why the old 3-pin fan on the white header now is running at a constant slow and quiet speed, I can suggest only that you MAY have "scrubbed" some oxide coating off the connector pins and improved its electrical connections to the header.