When I got the replacement cooler from Amazon, the first thing I did was to plug the fan directly into the power supply. When you do that, the expected result is for the fan to spin up at full speed - that is at 2000RPM. I made sure that the RPM limiter switch was switched to the performance mode as well. To my relief, the fan seemed to run at full speed though there was no way to confirm that the fan was hitting 2000RPM. But it definitely felt like 2000RPM, for the sound and the air flow generated from it.
But I wouldn't be running the fan directly off the PSU. I would be running it off the motherboard CPU fan headers. It wouldn’t mean squat if it cannot work with the motherboard. So to find out if if the motherboard truly wasn’t the culprit the last time, I plugged in the fan to the motherboard and luckily for me, it also ran at full speed. w00t!
There was no way in hell that I would be running the fan at 2000RPM. While it is not as deafening as the two TY-143’s I had on the Silver Arrow Extreme cooler, I still had to tame down the fan speed.
I managed to set the CPU fan speed to around 1100RPM, which is not exactly silent, but is quiet enough not to be distracted by. However, Asus UEFI doesn’t let you limit the max fan speed to a user’s setting of choice. You can limit it to some speed until the CPU temp hits 75C, but after that the fan is given the full juice to spread its wings.
So basically I set it to run at 1100RPM (or 30% PWM as per UEFI – wonder why it is different to what AISuite is showing in the pic above) when the CPU temp is below 65C. From that point to 75C, the fan will ramp up linearly up to 60% or 1500RPM. After that it will be a sudden rise to 2000RPM. Why I didn’t set it to ramp up to 2000RPM was because the fan speed would vary with the slightest difference in CPU temps and it is really irritating – more irritating than the fan running at full speed all the time.
I didn’t really check how much the temps would increase when I limit the fan speed to 1100RPM. But it doesn’t matter. When the need arises, the fan will also be switched to the full speed, so there is no risk of CPU overheating.
I wonder if adding a second fan would improve the temps, or more importantly, if I would be able to run the fans low while matching the performance of a single fan at full blast.
That said, I do have a second fan with me. Just that sadly it doesn’t speed up higher than 500RPM. (Need to send the fan before 21st iirc) But I can check whether or not it fits, and if it does, I can just buy a second fan. They are not cheap though.