Pump changing speed

[arconz]

I've had a new system build with an Asus Dark Hero motherboard and an EK D5 pump for a custom loop. 2 420mm rads cooling just a CPU at this stage (5950X), so kinda overkill surface area lol.

When I first got the rig they had set the pump to run at 100% constantly which was very loud at 4.8K rpm and totally unnecessary I think. Thing is when I set it to PWM with a temp curve in BIOS, it appears to change speed randomly even when the CPU is not really doing anything... this pump makes a fluttering sound whenever it changes speed so I want to avoid this if possible.

What are the temp curves others are using with a D5 and/or what is the best way to avoid frequent speed changes? Do I have something set incorrectly in BIOS? Thanks in advance.

 

[arconz]

Ideally you would have a temperature sensor for the water in the loop somewhere, and set a temp curve using that sensor.

It sounds like it's set to the CPU temperature at the moment, which spikes a lot for half a second at a time.

Ah... this is the problem, its set to CPU temp. Setting a constant speed for the pump is fine but it would be cool to have water temps as an option - so basically they will have to drain the loop to install sensors lol?

This is the store that is doing the assembly, would I need two of these parts? What would be the optimal locations for them in the loop? The Dark Hero has water in & out headers. My rads are EK Coolstream which have only dual ports, and my res is a D5 Heatkiller 200 using the default in-out ports. I have the multi-port top for it but they didn't install this.

 

[arconz]

You should only need one of those sensor parts, as the water temperature should be equal throughout the whole system, give or take a degree. I fitted mine to an unused inlet on the pump.

This is the EK pump I have.. its just a motor which attaches underneath the Hetkilller res. Would I have to install the multiport res top to get an extra inlet? Either that or remove that motor and install an EK pump which has a spare inlet, like the Quantum Inertia? Seems like the expensive option though lol.

Also should it attach to W_IN or OUT on the motherboard, doesn't matter?

 

[arconz]

If you need to control the temps and do not want to alter the pump then alter the fan speeds. It is a balance between pump speeds and fan speeds.

Yup that makes sense & I understand I don't need water temp info, but it would be cool to have the option (and it can also drive RGB lol).

Using no pump curve - assuming you wanted to keep the rad fans at the same speed - is it likely you would need a higher static speed than if you used a curve that was say 75% flat then had an increase for high fluid temp?

 

[arconz]

Find the pump flow rate you like and stick with it. If temps are ok and not too loud then enjoy.

Is this done by manually making the PWM Qfan curve "flat" or is there another setting where I can set a specific speed? (The rig is currently in the shop & I can't remember BIOS options).

 

[arconz]

I have the PC back and its working great with the pump set at 50%. I have the option to use water temp as I got the sensor installed anyway - it will be interesting to keep track of the fluid temp over the seasons [currently winter] and in different usage scenarios. Now at 22°C, that's with all 8 140mm fans silent at 900rpm