[SOLVED] Liquid Cooling Loop is running hotter than previous Air Cooler?

[chrischoythebuilder]

I've recently installed a liquid cooling loop into my pc to replace my previous air cooling unit for my cpu. With my previous air cooler, I was seeing idle temperatures around 35C. With the liquid cooling, I'm seeing temperatures around 45-50C at idle and 65C under stress (running cinebench). From what I've read, the goal for idle temps should be around 25-35C. My ambient room temp is at 25C and system temps are around 30-36C.

What can I do to improve my idle cpu temperatures? While I was not expecting a significant increase in cpu temps switching from air to liquid, I was not expecting it to get this much worse.

Technical details about my build:

• CPU = AMD Ryzen 7 3700X (PC Part Picker full build list)
• Case = NZXT 510 (compact mid-tower)
• previous cpu air cooler was the AMD Wraith Prism cooler that came with the cpu. There were no intake fans, just 2 exhaust fans in this setup.
• Liquid cooling loop is the EKFluidGaming A240 kit with custom hard tubing and EK fittings
• Radiator is positioned in the front with 2 120mm Vardar static pressure fans positioned in a pull configuration (fans and rad came with A240 kit)
• No overclocking or custom configs are being used for the cpu. I'm using the same default stock config that was being used for the air cooling setup.

Other info from troubleshooting attempts:

• Pump is definitely on and working. Aside from vibrations coming from pump, this is supported by the fact that temperature also sits at ~48C rather than continuing to increase in temperature every couple of seconds.
• Fan direction is correct
• From what I can tell, loop is free of air except for a few bubbles trapped in the reservoir. I tilted the system a bunch to try and free any bubbles trapped in the rad and cpu block.
• Radiator is slightly warm to the touch, but otherwise is mostly cool with cool air being pulled into it.
• Thumbscrews on cpu block are tightened sufficiently.
• Appropriate amount of thermal paste (EK-TIM Ectotherm that was enclosed with A240 kit) was used and inline with online recommendations (2 rice grains/size of a pea).

This is my first pc build ever and my first attempt at a liquid cooling loop. So any feedback/suggestions are appreciated! Thanks!

 

[kerberos_20]

which way water flows?
nvm, figured it out from your blurry pictures
cool radiator is fine, it means it still has headroom left
can you increse waterflow? Point of watercooling is to transfer heat from cpu to rad as fast as u can, and at same speed it will get cold water to cool it down

tube comming from cpu with hot water is hot? 40~50C should be noticeable

 

[rubix_1011]

Those aluminum EK Fluid Gaming kits are actually pretty solid performers as long as you maintain only aluminium components in the loop...(don't want to introduce/expand using copper, nickel, brass, etc)

I forgot the flow direction on the pump....let's see...outlet on the left, so pump -> radiator -> CPU block -> pump

Loop order doesn't matter and your CPU block inlet appears to be used correctly.

Is there flow? Can you see turbulence in the reservoir? It should be very apparent on a loop that small. If you vent the reservoir cap, just loosen it, does it make any difference?

 

[chrischoythebuilder]

Pump and cpu block inlets/outlets are correct per the kit's instructions. And the ordering is pump > rad > cpu > res. Tube coming out of cpu was warmish? I also re-uploaded the photos in the og post to have a higher resolution.

I can see turbulence on the surface of the reservoir. And that did actually point me towards realizing one optimization and discovering why I would get such good temps under stress, but poor temps under idle. My intake fans and pump are hooked to the same Y-splitter which hooks them all to the CPU_FAN header on my motherboard. I had this set to SILENT mode to reduce fan noise. So the fan curve that was controlling pump speed would have it at around 40% speed around 40C and 100% at higher temps past 60C.

I tried setting the CPU_FAN to 100% at all times to see what would happen. Now, where we saw a mostly stable 47C at idle, we now see the temperature fluctuate pretty rapidly (1 degree/s) in the 36-47C range. System temp is still the same at around 32C stable.

This is better, but still not quite the performance I was hoping for? It's weird to me that the temperature fluctuates so much now. Any other ideas/suggestions?

 

[kerberos_20]

its usualy better to have pump running at full speed on one fan header (cpu_opt) and fans with variable speed on another with y cable (your manuals mentions that)

that cpu temperature fluctuations u see could be due to not enough ampers when connected all things into single header
it could be also low pressure between water block and cpu ihs

 

[rubix_1011]

Yes, agree. Choose a pump speed and leave it there, or leave it at full speed. They are designed to operate like this.

As for fans, the curve used might need to be adjusted over time - start with a 100% curve under full load and make note of your reported temps. 100% utilization should be running high enough fan RPM to handle the loads while the flow rate from the pump should be constant (if possible). Then, do the same for idle...note temps. Start plotting your curve with these load/idle temp points in mind and begin to visualize what 50% and 75% temp should be for fan speeds.

It might take some adjustment, but good rule of thumb with watercooling is to start at full speed and work your way back. At least that way you have knowledge of the full capability of the system.

 

[chrischoythebuilder]

Sounds good. I'll need another fan extension cable for the pump to reach, but I'll give it a try once I can. Thanks!

 

[EndEffeKt_24]

Due to the smaller chiplet in the lower corner of the cpu there are known problems with transferring heat from the chiplet to a waterblock. This is partially the case because most blocks are designed to dissapate heat best from the centre.