Thanks for the tips guys, much appreciated. I also found that controlling fans in AI Suite does not work properly with water in/out sensors so I'll try T_sensor 1.

davemon50 wrote:
Will something like THIS work in your loop? Plugged into one of the board's supplemental temp sensor locations? (in lieu of the water cooling sensor)

I am using Barrow sensors that are identical to these (without the LCD display). I'll try hooking one up to T_sensor 1.

Ashwind wrote:
I plugged my temp sensor into T_sensor 1 plug on MB and that was the only way I could use my loop temp to control fans on a maximus IX

Yep exactly what I was suggesting. Sounds like it will work. The sensor above looked like a nice one to me.

billb wrote:
Controlling fan speed based on water temp is a bad idea.
In a few minutes the water will get hot, the CPU will get hot, and the fans will run continuously.
...

There are so many out-of-context assumptions in that graph I'm not sure where to begin. It's very misleading. And why are you throwing that out there anyway, is this a real case study of your own PC or did you copy it from some form answer somewhere.

First is you are showing stepped fan control, not variable. Second the steep curve on the CPU temp is being shown as a direct result of a slow temp rise on the water circuit after an immediate stressing of CPU. That however is entirely dependent on the unique system heat exchanger capacity and efficiency, water volume flowrates based on actual system volume and pump size and capacity, speed control baseline of the pump, and several other factors such as the CPU capability itself and overclocking. It's system dependent. Not even to mention that what you are showing appears to be an immediate stressing of the CPU such as a high end gaming or stress test, which is typically followed in every single system by a marked fan flow and/or pump flow and sound increase. Unless you are use refrigerated cooling you already get that.

That first part of the curve I assume is system startup, even though it's not labeled in any way, first heat cycle has no meaning. That said I assume the part in the middle is indicative of system idle? Again no label, but the CPU temp drops and the water temp only partially drops because this chart is saying the fans stop or go to min at idle. That is completely dependent on how you program the BIOS or heat rejection utility. Those curves can be as aggressive or passive as you like, dependent on your hardware and on your heat rejection equipment. You can bring that idle water temp down too if you feel like it, subject to your equipment capacity, so you don't get into some spike like this chart shows.

All this is completely out of context and some coined response for a specific setup and application strategy. You're trying to negate a whole cooling strategy in one fell swoop based on that. Totally misleading. It would have merit in a specific configuration and cooling strategy.

billb wrote:
Controlling fan speed based on water temp is a bad idea.
In a few minutes the water will get hot, the CPU will get hot, and the fans will run continuously.

Hello
If the option is available to control radiator fan speed based on coolant temperature that is the method that should be used. If the coolant gets hot after a few minutes of CPU load either something is broken or the water cooling system is worse than poor.