I have a Coolermaster HAF932 case with three 200mm fans and one 140mm fan. The cpu has a separate fan. The case has good air flow.
My motherboard is an Asus p8z68 deluxe/gen 3. All fans are plugged into the motherboard although only two are adjustable.
Would it be a waste of money to get a fan controller just to allow adjustments to the fans that are not adjustableon the motherboard?
If not, do you have any recommendadtions?
It's a waste unless your system is making too much noise for your comfort or you simply want to make it more quiet. The real question is whether the money for a fan controller is worth the benefit you will receive from the controller.
I love my fan controller...extra airflow if I need it but QUIET all the time. I have every 120mm fan in my case set to rotate at 1000RPM and I've never had any noise or heat issues. Have you tried adjusting your GPU fan with a program like Speedfan?