From my understanding a PWM fan is exactly like a non PWM fan and should work exactly like one, but a non PWM fan cant work like a PWM fan.
A 3 pin fan has a ground, a voltage input, and a tach out. To adjust the speed you raise and lower the voltage of it's input.
A 4 pin fan has the same ground, voltage input,tach out, but adds a fourth signal line.The voltage input is kept at constant 12 volts in a 4 pin plug layout. This signal line uses alittle chip to measure the % difference of the signal it receives ,between on an off. If it gets 100%signal the fan will not run. If it gets 50% signal it runs at half its rated speed. If it get no signal(like when you plug it into a 3 pin plug)it runs at 100%. The fact that it does this lets you adjust the input voltage going to it and run it exactly like a 3 pin fan.
PWM fans are designed to get around the high start up voltage of some fans. Say your CPU was reporting to a certain 3 pin fan to run on 5 volts, but the fan needed 7 volts to start. It might not start on boot and let the CPU raise in temp until it says to the fan to run at 7, or the motherboard manufacture has to put alittle program in the BIOS to force the controller to put out 100% to spool up the fans on boot to get past the problem, than settle back down to 5 volts.
With a PWM fan you dont have this problem if the CPU will tell the fan to run at 40%, and it will because it has a full 12 volts to start, and it will free wheel thru the 60% of the time the CPU tells it not to run.
so yeah long story short you should have no troubles.
