[thatsboot3101]

I have an EK-DDC 3.2 PWM pump that gets power via molex and is also plugged into the CPU1 4-pin header on my motherboard. I'm having a problem where the pump will only run at a high RPM (over 4k) or low (somewhere around 1k) and nothing in-between. For example, regardless if it's set in the curve to run at 10%, 20%, 30%, or 40% it will run at 1k and if it's set to 60%, 70%, 80%, 90%, or 100% it will run full tilt. I've done some googling to see if anyone else has had a similar problem but I couldn't find any solutions. Anyone have any ideas?

 

[VSG]

The DDC PWM pumps have a short duty cycle. The control range is usually within 25-65% PWM signal, if not even narrower than that.

 

[thatsboot3101]

Quote:

Originally Posted by geggeg

The DDC PWM pumps have a short duty cycle. The control range is usually within 25-65% PWM signal, if not even narrower than that.

Thank you! That's a huge help, I didn't know that. I had been trying to set a manual % and my motherboard only allows manual settings in 25% increments. Would it be better to set up a curve between 30%-70% or just a fixed speed? It's pretty loud on full blast(case resonance and all that) and actually gets pretty warm to the touch. I wonder how much heat it's actually dumping into my loop.

 

[VSG]

Try to decouple it using some foam pads. It does get warm when used at full speed in a not so restrictive loop, but that doesn't really get transferred to the loop. You may want to invest in the heatsink kit though.

Yeah, that's a terrible fan curve you have. Try 30-70 and see.

 

[tsm106]

Quote:

Originally Posted by geggeg

The DDC PWM pumps have a short duty cycle. The control range is usually within 25-65% PWM signal, if not even narrower than that.

The pwm ddc has variable dc from 10% to 100% however as Martin showed the ideal or highest dc level with lowest trade off point is around 52% dc. In other words you get 95% off the pumps power at just over 50% duty cycle.

Op, I've haven'tt much experience with MSI PWM control but from what I recall it is rather limited. With something like Asus, setting pwm dc according to temp is very easy. There are different explanations on what Msi defines their dc by it never made much sense to me lol sorry.