If two fans share the same PWM connection port will the speed be the same?

[Jonas Magnusson]

as the title says, a little info on it all:
My laptop has been running hot the last year or so and the cause is that one of the two fans didn't spin. It wasn't a bad fan because I switched the places with the fans and the problem occurred on the other one on the same port. I then proceeded to cut the blue cable so the fan spins 100% all the time which vastly improved thermals with near on full load ~40c though it was louder.

I wonder if i solder together both blue wires and run them of the working port will the speed be the same as it was for the working fan on both or double/half the speed? By that the red yellow and black will still run of their respective ports as usual, only the blue PWM will be connected to the same port.

For home usage it is fine as it is but I plan to use it in my university when I'm going to program and it being as loud as it is it would be disturbing. Both fans need to spin otherwise it would thermal throttle and become uncomfortable to use.

 

[Paperdoc]

Yes. If your fans have the same colour codes as some AMD 4-pin fan systems, the Blue in on Pin #4 of the connector - that's the one outside the set of two ridges on one side. Connecting both blue wires together to a single mobo fan port will send identical PWM signals to the two fans and they both will run at almost identical speeds. And those will both be fully correct speeds, not half what they should be.

 

[Paperdoc]

Thanks for Best Solution.