>>1558614There's usually just one designated pump header, next or near to the CPU_FAN header. While you can technically plug the pump in any of the fan headers I believe, the pump header can (usually) supply more amperage. That being said, I'd check if you can actually do this; the voltage might be different.
If it's possible, the cleanest solutions would be to flash a GPU BIOS with your desired settings. Just make sure to test and see what the min pump percentage is before it starts AND stops. You really ought to set the minimum speed above both values. After doing so, you should monitor temps and see if everything works well.
Also, sometimes the pump noise is exacerbated by improper radiator positioning. You should make sure you've done that correctly.