H115i Platinum : Coolant temp not increasing

Hey guys, I'm making a post on the forums since Corsair seems to be having issues replying to support tickets swiftly.

 

Like many of you, I built a new rig last month with the release of zen2. The full specs are in my profile.

 

I paired the CPU with a H115i Platinum.

My current setup has the 280mm rad setup as a front intake with 4x ML-140s in a push-pull config. I've got 2 additional ML140s setup as bottom intake fans and two other 140mm fans that came with my case as top exhaust. I've also got two 120mm 1850rpm Gentle Typhoon fans in push-pull with my GPU radiator setup as a rear exhaust. So overall I'm assuming I've got more than decent airflow.

 

Here's my issue. While the temps I'm seeing seem OK at best (80C under a full Prime95 small FFTs test with all fans running at 100%) the reported coolant temps in Corsair iCue is wrong.

 

At idle my coolant temps is around 24.5 - 25C while under load it doesn't even go up by a full degree. My ambient temperature is at 24C.

I'm pretty sure that my idle coolant temp should at least be a couple degree above ambiant. Under load I'd expect and additional 6-10C rise in coolant temp. Please see the attached screenshots.

 

I placed my hand on the tubing while the benchmark was running and it doesn't feel warm at all and I don't feel any or much flow. iCue seems to be reporting my pump speed correctly at 2800rpm.

 

I tried re-seating the block three times and I also used different thermal paste just to be sure. I'm getting near identical results each time.

 

Anyone ran into a similar issue? Anyone thinks I might have a defective unit?

 

Thanks!

Edited August 10, 2019 by krusty50
typo

So ... a couple of things.

First, you're running the fans at full blast. It's shedding the heat pretty much as quick as you create it.

Second, that's a six second Prime95 test. You won't see the temps move much, if at all, in that short a period. Especially with running the fans at that speed.

Liquid takes time to heat up ... and cool down.

 

Drop your fan speeds a bit. Run Prime95 for 30 minutes. Then see what it does.

So ... a couple of things.

First, you're running the fans at full blast. It's shedding the heat pretty much as quick as you create it.

Second, that's a six second Prime95 test. You won't see the temps move much, if at all, in that short a period. Especially with running the fans at that speed.

Liquid takes time to heat up ... and cool down.

 

Drop your fan speeds a bit. Run Prime95 for 30 minutes. Then see what it does.

 

I reran the tests just to grab screenshots but I can assure you that I'm getting pretty identical results over 30+mins of SmallFFTs. The test in my screenshots was 6 minutes not 6 seconds btw.

 

If I lower my fans to more acceptable levels sound wise (around 50% / 1100rpm) I get identical results in regards to CPU and coolant temperatures. I've never seen my coolant go over 25.6C. I don't think that's a realistic value given the fact that it's trying to cool a 65W load at 24C ambient.

Edited August 10, 2019 by krusty50
typo

So ... a couple of questions.

1) Are you running any other monitoring tools?

2) How does the fan exhaust feel?

3) What are the CPU temps?

 

... and, tbh, a 65W load for an H115i isn't much at all. That's a pretty light load. My H115i handled my Threadripper - a 180W TDP chip - and never went over 38C in a 27-28C room.

So ... a couple of questions.

1) Are you running any other monitoring tools?

2) How does the fan exhaust feel?

3) What are the CPU temps?

 

... and, tbh, a 65W load for an H115i isn't much at all. That's a pretty light load. My H115i handled my Threadripper - a 180W TDP chip - and never went over 38C in a 27-28C room.

 

I'm only using HWinfo64 for the CPU and Precision X1 for my GPU. I disabled the reporting of the AIO's status in HWinfo as per Corsair's support article.

 

The air exhausting from the back of the rad doesn't feel warm at all.

 

The CPU will hit 80C in prime95 and CinebenchR20 while some other benchmarks (ie: wprime) seem to be less intensive and usually over around 50-60C.

 

I've looked at reviews that benchmarked the 3700x temperatures and the results are all over the place since they're not all using the same benchmarks. Some sites are using the stock cooler while others use an AIO or a custom loop.

 

Quite honestly my temps *might* be OK but it still doesn't explain while my coolant temp isn't fluctuating. I can't even use the default fan curve in iCue since it's based on coolant temp.

The coolant temp is the proper variable to use. CPU temp is irrelevant to the radiator fan speeds.

Set the fans on Quiet and the pump on Quiet. Run a CPU stress test and record the readings. Post the results and we'll take a look at it.

TBH, I don't think that you have an issue. I think the real issue is that the cooler is getting rid of the heat as soon as you create it - which isn't really a bad thing. It really isn't going to be worked hard by a 65W CPU, even at full blast.

The coolant temp is the proper variable to use. CPU temp is irrelevant to the radiator fan speeds.

Set the fans on Quiet and the pump on Quiet. Run a CPU stress test and record the readings. Post the results and we'll take a look at it.

TBH, I don't think that you have an issue. I think the real issue is that the cooler is getting rid of the heat as soon as you create it - which isn't really a bad thing. It really isn't going to be worked hard by a 65W CPU, even at full blast.

 

I attached a screenshot of a Prime95 SmallFFTs 15 minute load using the quiet settings.

 

With the fans barely spinning my coolant temp slowly rose up to 28C. The air coming out the AIO was slightly warmer this time.

 

The CPU temps also went up by 3-5C up to 83-85C. The CPU automatically adjusted his all-core clock to ~3.95ghz compared to ~4.125ghz when the fans and pump are running at full speed.

 

I'm guessing that's just the nature of these new zen2 chips. While the TDP isn't that high (65W) the Tctl/Tdie temperature can still get quite hot since all that heat is coming off that single little chiplet.

 

I don't think I'll ever be able to use iCue to setup a fan curve based on coolant temp since I only get a 1C delta (~24.5C @ idle and ~25.6C @ load) in my coolant temps when the pump is set to "balanced".

Edited August 10, 2019 by krusty50

Hi i have the same problem, did you find a solution?

Have the same problem with the water cooling of H100i ELITE CAPELLIX Liquid CPU Cooler, temps don't go up when I stress my cpu

The change in coolant/liquid temperature is a function of the power output of the CPU, not it's temperature. Fans help dissipate heat from the liquid and they do not cool the processor directly. Your CPU is heated as a result of the voltage applied underneath and that heat is conducted into the cooling system. The liquid, fans, pump, and radiator are like a waste removal system. It picks up the waste heat and blows it off somewhere else. We can make massive wall sized cooling apparatuses, but that only disposes of heat in the liquid. It cannot prevent your CPU cores from hitting 100C when you apply 1.50v to the CPU. Voltage is the limiting factor for nearly all CPUs.

 

Your specs are not listed, but smaller die size, low TDP CPUs like many of the Ryzen series chips do now have high power usage and thus will not cause a large change in coolant temperature even when maximally loaded. Since coolant temperature has a +1=+1 relationship with CPU temp, you don't need to worry about the cooler settings very much. If the coolant only increases +3C, then your CPU temp is only 3C higher than it would be if the fans and pump are at maximum. That is going to be a small part of the total CPU temperature. However, the longer you run the load, the more heat can build up. Still, you likely do not need to use high fan speeds and they will not provide further benefit.