Hydro Series™ H100i PRO RGB measures wrong Temprature

[CoolAsIce]

Hi everyone,

 

a short while ago I've upgraded my system with liquid cooling. Afew days ago I've realized that the H100i Pro is taking the case temprature for controlling the pump. No matter if my CPU is at 50 °C goes up to 70°C, the speed of the pump won't change.

 

Is ther anything I can do ?

 

iCUE is also showing the wrong temprature.

 

[c-attack]

The value on the cooler page in iCUE is the coolant temperature. That is your control variable for fan speed and a more efficient one than cpu temp. Your cpu temperature is the end result of the heat created at the socket pins where voltage is applied and the physical properties of the CPU. Whether you use air or water to transport heat, there is a minimum CPU temperature you cannot get under based on the two factors above. When you load up 1.45v on 9700K, you’ll hit 95C a fraction of a second later. It doesn’t matter whether you have a little Intel fan or a 10ft tall exterior cooling panel. All that heat created at the pins must be conducted through the cpu to get to the cooler. The “cooler’s” job is to keep the temperature from getting worse. The little fan will be overwhelmed in seconds. The 10ft panel can go perpetually at the same temp with no further rise.

 

The fans, radiator, and pump are like a second stage of cooling. The first part is conductive. The cooler is more like waste heat removal. Pick up the trash heat from cpu, dump it elsewhere, go get more. The key element in this is heat goes both ways across the cpu cold plate and the coolant temperature is the minimum possible cpu temperature with zero voltage. Even when at load, +1C coolant temp means +1C CPU temp. If you keep your coolant rise at 0, you are as low as you can go. In reality, none us are using 10ft tall radiators and some coolant temp rise is inevitable. On a 9700K and 240mm radiator, you are likely to see a +6-8C change. That is the value you are trying to minimize with fan speed changes. However, -2C may not be a valued exchange if you have to use loud fan speeds to achieve it.

 

One thing I do recommend is getting off the Quiet/Leise pump speed (1100 rpm). This is ok for quiet word processing, browsing, etc., but it will cost you 5-8C or double the normal coolant delta at any level of load. The medium balanced/balanciert speed (2160) should be fine, but you can test out the extreme 2850 rpm as well for stress testing. Pump is a fixed/manual change - not dynamically adjustable. Go to the performance tab, click on “balanciert” (it will highlight yellow), then click on the pump. It should “ring” yellow as well and change speed.

 

You can add the normal cpu and core temps to the dashboard with the “+”, system info, and selecting motherboard, GPU, or anything else available.

[CoolAsIce]

Ha, now this makes sense !

 

I'm new to this so thanks a lot for this very detailed information. I'm sure I will have a few more questions the next few days :D

[CoolAsIce]

@ c-attack

 

Now a day later and reading your Reply again, this makes so much more sense to me now :)

 

Playing aorund a bit comparing to what you have posted was an eye opener.

 

Using Handbrake to encode videos (which I do often) and watching the coolant T and CPU Core T is interesting now :)

 

On Extreme everything my Core Temp gets down to 56°C +-2°C, while on blanced fans and extreme pump its 64° C +- 2 °C

 

Is there a point of not always maxing the pump as it's at least for me not hearable at all. The fans get noisy around 1500rpm, (no surprise) I just wonder if "better" fans would make better cooling at lower noise ?

 

Well over all...64ish °C while encoding video is acceptable I guess.

 

I was coming from an incorrect mounted CPU fan going easily 90+°C to a correctly mounted one at 85+°C to a now liquid cooling system at around 65+°C Igiuess I'm a happy puppy now :D

 

Corsair should use your posting and send it alongside any cooling device, I guess starters, like me, will help this a lot :)

 

PM me your paypal or Amazon whish list dude !

[c-attack]

That is a slightly bigger gap between the Performance and Extreme fan presets than I expected, however that may be more realistic on a 240mm radiator with any of the 9700/9900 variants. Just remember those are not "smart" fan curves that automatically adjust themselves to your conditions. There are pre-programmed data points (Temp X = fan speed Y) like any other curve. To that end, you are going to want to eventually move to curves of your own design. (Performance tab for the cooler, hit "+" to create a "cooling mode" - not sure of translation used in iCUE)

 

The trickier bit with balancing your fan curves with water cooling is the room temperature is always your floor or lowest possible temp. The problem is the floor moves. With air cooling and CPU temp control, we don't care about what happens when the CPU or baseline fan curve is moving from 25-35C. It's flat, the fans don't respond. But with water cooling and coolant temp, the jump from 25C coolant to 35C coolant is a large change. That is complicated by normal room fluctuations from morning to evening in warm climates or because of accumulated heat in the case. In the end, most people in temperate climates will want at least a "Winter" and "Summer" curve and maybe one for in between. Your coolant delta or total change from baseline to max is always going to be about the same (the 8-10C), but the starting point or baseline temp will change with the seasons. Those presets were designed with a cool 20C room temp in mind. It will work fine in Winter, but in Summer the fans will be blasting from the moment you power on. There is no point in this since you can't reduce the coolant temp below the room/case temp.

 

The easiest way to make the curve is to power on the PC and let it sit for 10-15 minutes (or do your normal web browsing, word processing, etc.). Check coolant temp. This is your baseline. Set a quiet fan speed for this temperature. Now set the highest fan speed you can tolerate (say 1500 rpm) to the highest coolant temp you see (probably about 10C higher). What you do with the dots in between is up to you. Leave yourself a 3C flat zone at the bottom to account for daily temp variations. You don't want a 200 rpm fan spike when it goes up 1C. Set a 2000 rpm fan blast for somewhere out of reach, like 45-50C. If you hit this temp, you'll want an auditory warning. That should do it.

 

Fan choices - The ML series are good radiator fans. You won't find something that outperforms it in the same 900-1500 rpm range. You can slightly reduce temperatures further by pushing into the extreme range of fan speeds (2000 rpm+), but as you have already noted and I agree -- it's a lot of noise. 1500 rpm is about my limit for 120mm fans. Now, if you fall into the category of super critical/picky about sound texture (I do), then you might experiment with other fans to try and change the tone in the rpm range you do use. However, performance gains will be hard to find and you should only do this for better appearance or a more pleasing tone.