H115i full fan speed under Quiet/Custom Profile

Hello,

I'm having an issue where my H115i cooler surges to max fan speeds even under the quiet profile or under custom when I set the top limit to anything over 59%. This appears to happen when the cooler temp hits around the 113F mark.

 

If I set a fixed % in iCue this doesn't happen. The fans stay at whatever level I place them at. Is there a bug in the iCue software that it letting this happen?

 

I've already set Q-fan for the CPU header to off/Maximum so it should be controlled only by the pump.

I'll have to gather some screens of the curve and post them but the behavior also occurs on the built in profile including "quiet" which seem like it should cap the fan speed at a lower level unless I'm misunderstanding the preset. In general I try to keep the max speed around 60% for noise purposes but at around 110-114F the fans start surging and eventually go to the max of 2200 RPM

We probably also should figure out why your coolant temp is getting to 45C. That’s an awful lot for a 5930K. It would only make sense if your room/case temp is over 37C and I wonder if you’ve reached a pre-programmed fail safe point with the fans.

So I currently have my custom curve set up like this with the max % set to 80. If I lower the max to be under 60% or use the quiet preset I experience the issue. Icue version 3.13.94

In the screen shot your coolant temp is 29.8C and this is probably at idle. Are you saying you get to 45C coolant temp when under load?

First, that fan curve looks to be more appropriate for CPU temperatures, not coolant temperatures. Coolant temps are going to be significantly lower than CPU temps and if you ever get to 80C on your coolant, you have real serious problems. Take a look at the Liquid Cooler FAQ in my sig for some guidance on the fan curve.

 

I would lower the max temp to around 40-45C.

 

Next ... at what coolant temperature do you see the fans kick off?

The 80c is just me experimenting to try to avoid the issue I'm experiencing where it goes to max settings.

 

I'd like to set the max fan limit at 60% around 40-45c but I'm getting this weird surging where it revs the fans up to max and back down very rapidly before staying at max until I close out the game.

 

Oddly enough if I switch to a fixed percentage it responds normally. I'd say under max load it's getting to 113F (45c) which would normally be around 60% fan usage but it starts that surging thing instead of following the custom curve or preset quiet limit at around that temp.

 

I'd understand that I'd need to raise the speeds if I were overclocking or something but these are at stock voltages.

 

*It just started doing it at exactly 40C. Looks like the fan started surging from 1500 to 2200 in wild jagged spikes instead of a smooth transition.

 

*Ok I think I figured something out. As long as a I put a point at a higher temp then it seems to follow the custom curve normally. But if the temp gets higher than my highest point then it surges to 100%. So I have to put in a random outlier like 64C and as long as the temp stays under that I can keep the fans at 60%. Unless something is wrong with my unit this seems like a bug (admittedly I may be doing something wrong)

So ... under what conditions is your cooler hitting 40C? Gaming? Something else?

 

Can you describe the airflow in your system? How many fans and placement?

 

I suspect that your GPU is dumping heat into the cooler and that's the root cause of the issues.

It hits 40c while gaming for a normal period of time (about 40 minutes). I've got the radiator mounted to the top of the case pulling air in from the vents at the top. I've got a rear case fan exhausting air out of the back and two front fans pulling air in at the front.

 

The GPU is the FTW3 model with the three internal fans on the video card.

 

I guess my main confusion is instead of the highest point in iCue being a hard limit it appears that under certain temps the fans go to 100% no matter what you have set in iCue. If this is some sort of fail safe then I understand, but I'd like to be able to see this represented more clearly so I can adjust my speeds to avoid hitting that limit.

I thought the old "fans kick to max at 40C" thing had been removed from the custom fan curves long ago. However, I don't think that should be the main focus at the moment. If you are seeing a coolant jump of +15C with 5930K at any clock speed, something isn't right. I ran a 5930K@4.5GHz on a 280mm cooler for a long time. Normal load coolant delta was about +6C at 200W+ and my fan speeds were lower than yours.

 

As mentioned above, the GPU could be affecting things, so it is probably time for a quick CPU stress test to remove that element. Run something mild like Intel XTU, AIDA64, or even OCCT for 10 minutes. Use a fixed fan fan speed to cut out the other issue. 1250-1300 rpm is enough. Note the beginning and ending coolant temps. Also watch how long it takes for the coolant temp to drop after the test. In this scenario, it should drop 2-3C in less than a minute and another 1C every minute or so after that. If the coolant stays up, that also suggests a problem.

Ok so I just purchased the EVGA Hybrid kit for the GPU and it uses a blower style fan that should help exhaust GPU heat out of the case. I'm going to install this weekend and run more tests on the coolant times. Do you guys think installing the radiator on the front of the system would be beneficial as far as air flow goes? I do have a desk above the case but there is maybe a 9 inch gap and all sides are open so it's not in a cabinet or anything. I've also considered maybe putting the case on top of the desk to maximize airflow.

Jettisoning the GPU heat out the back on the 120mm radiator will reduce internal temps quite a bit. I ran my 280mm CPU radiator top exhaust, 120mm GPU Titan hybrid rear exhaust for a long time. Temperatures were pretty laughable. Yes, I could drop CPU coolant another 2C by moving it to the front intake. The top layer of your case is typically warmer than the bottom or front rail by the same amount. 2C is not much to get worked up about and I would not compromise your overall design for that. My case had a lot of rear mesh, so it was easy to push air front the front and have the remainder go out the radiator or ventilation. Very efficient. In something without a lot of rear venting, the front CPU radiator may have more benefits.

 

***However, still a little concerned at the coolant temps. +15C is a lot even factoring in GPU heat. Run a quick CPU only test. Coolant delta should be about +6C in 10 minutes. A lot more and something is wrong.