Pump PWM?

[BobRoss]

Has anyone tried or heard of trying pulse width modulation to control the speed of the pump in a Water Cooled machine? Maybe have it linked to a temp sensor for instance?

[Gizmo]

Would only work if you have a DC pump, and I suspect it would be rather tricky to implement in practice, owing to inertia of the water in the cooling loop, and the pressure drops across the water block(s).

It would seem to me like the smarter approach would be to use speed controls on the fans. Although PWM on the fans is usually not practical (because many fans already have a PWM controller internally, and two PWM controllers in series is a recipe for disaster), it's easy enough to control the voltage to the fan with a linear regulator, and control the speed that way.

[ThunderRd]

Some newer boards with ESA support can do it via nVidia system tools v6+. But the board and the pump have to be compatible with ESA. The software is a bit buggy yet but it does work on my main rig. I can adjust both the fan speed and the pump speed and can set loadable profiles for both. There are sensors on the coolant volume through the pump, the coolant temp into the pump, and the fans.

[Gizmo]

Originally Posted by ThunderRd

Some newer boards with ESA support can do it via nVidia system tools v6+. But the board and the pump have to be compatible with ESA. The software is a bit buggy yet but it does work on my main rig. I can adjust both the fan speed and the pump speed and can set loadable profiles for both. There are sensors on the coolant volume through the pump, the coolant temp into the pump, and the fans.

I'm curious; given that you can control the fan speed already, what's the benefit of controlling the pump speed as well? From a noise management perspective, I would think controlling the fan speed is going to help more than controlling the pump speed, so is there some other goal here?

In addition, I've not really spent a lot of time thinking about this, but from a systems management perspective it would seem to me like controlling BOTH fan speed AND pump speed would complicate thermal management, as you would now have a continuous spectrum of settings that would result in a particular temperature, trading fan speed against pump speed. Automating this tradeoff would not be a trivial task, I wouldn't think, without making some simplifications that would eliminate most of the advantages.

[BobRoss]

Well the pump i have is sort of loud and I think it is way more pump that I really need for my setup.

But what I was thinking was that I would throttle the pump back to a fixed setting and have the fans be variable to control temps.