3pin to 4pin case/cpu fan adapters?

[floydshayvious]

Hi everyone!

I'm repairing a computer that I gave to a friend - the motherboard died recently after several years of faithful use. I've gotten everything up to par with a new board (msi 760gma-p34(fx)) and have one issue. The new motherboard fan power headers use four pins, and the fans I have use three pin connectors. I read around here for a day and found out that it's possible to plug them in anyway - but they run at full speed non-stop because that fourth pin on the board is for PWM according to chatter here.

I'm just wondering if it's possible to buy little power cable adapters that plug into the 3 pin connectors from the fans, turning them into four pin connectors at the end so I can utilize PWM and not have to buy a new system fan and cpu fan/cooler to save a little money and not have to mess with taking that cooler off and mucking with the CPU again because it makes me nervous (lol)..?

Looked around but I'm not sure if they are a thing?

Thanks in advance.

 

[cin19]

I'm just wondering if it's possible to buy little power cable adapters that plug into the 3 pin connectors from the fans, turning them into four pin connectors at the end so I can utilize PWM

It does not work that way, because the fan has only 3 wires even you add other 3 to 4 pin adapter, it is still 3 wires fan.
If you want to control the 3-pin fan speed you have to buy the fan controller.

 

[burdenbound]

Are the chasis fans running at max speed actually causes any noise issues? Most case fans are designed that way and I have yet to run into one that is noisy. Your CPU fan should be connected to a 4 pin CPU header and that fan can probably get up to speeds where it's useful but most standard chasis fans don't spin up that fast.

If you do need to control speed then you will need a fan controller like cin19 said, or depending on the motherboard you may be able to control it to some level in the bios.

 

[floydshayvious]

Thanks for explaining it y'all - yep just going to have to put in a new system fan and cpu cooler/fan. The bios does have some settings but no matter what I change the percentages to they do not respond. Too bad I can't replace JUST the fan on the stock AMD cooler I'm re-using. It's...like...clamped to the heatsink - no screw holes Now to see if I can do this right and everything should be good!

 

[Paperdoc]

The manual for that mobo is minimal, but on p. 21 its labels for the three fan headers provide clues. For the CPU_FAN header it appears it IS a true 4-pin header operating in PWM Mode. Any 3-pin fan plugged into that will always run at full speed with no control. To achieve automatic control of the CPU cooling fan it would have to be of the 4-pin design. Bear in mind that, on many CPU cooling systems, the FAN part is replaceable easily without replacing the entire cooler assembly. Further, most use standard fan sizes so finding a 4-pin model to replace the existing 3-pin one is not hard.

The SYS_FAN1 header has 4 pins, but its labels indicate that it is NOT a true 4-pin header; it is acting as a 3-pin header using Voltage Control Mode. In that case I would expect any 3-pin fan plugged into that to be under mobo speed control. Are you sure this one is NOT changing its speed? If you can verify that it DOES change the speed of its fan, you do have an option that can help. Virtually all mobo fan headers can power up to 2 fans (not more) if you use a Y-splitter to connect them, so you could get two 3-pin case ventilation fans under automatic control this way. On the other hand, if this fan does NOT change its speed at all, then replacing it with a 4-pin fan won't change things IF the labels shown in the manual are correct.

The labels for SYS_FAN2 appear to indicate that it never tries to control the speed of its fan by reducing the voltage on Pin #2. If that is true, then that fan will run at full speed all the time. That is an unusual design - most 3-pin fan headers DO allow for speed control via Voltage Control Mode. So just check to be sure whether or not this fan is changing its speed. If it is NOT, then substituting a 4-pin fan on it will not improve the situation.