Noctua NF-F12 Industrial not spinning with H100i RGB Platinum

Hi there,

I've just put a pair of Noctua NF-F12 IndustrialPPC 2000 PWM fans on my H100i RGB Platinum.

But they only seem to spin up when I set their RPMs to 100% in iCue. Otherwise they just won't spin. This is when connected to the fan headers coming off the H100i's pump.

If I use a Y-cable to connect them to the motherboard fan header, they spin up just fine. But I lose the ability to control them with iCue, and all the other benefits of being controlled by the H100i.

These fans keep my Ryzen 7 3700x a full 8-10C cooler when stress testing with Prime 95, vs the Noctua NF-F12 chromax that I had on before.

The chromax worked fine when connected to the H100i's fan headers.

Anyone run across this and have a solution? Or have any idea what could be going on here?

Thanks!

You can try swapping the connectors on the splitter 1<->2. However, this is more characteristic of incompatible PWM tech than a wonky splitter. This behavior has been an issue on the 3000 PWM Industrial only. I used the 2000 rpm version in both F12 and A14 form for years on Corsair controllers as have many others, so it’s not clear if the Platinum PWM controller is different or there is a more basic reason.

These fans keep my Ryzen 7 3700x a full 8-10C cooler when stress testing with Prime 95, vs the Noctua NF-F12 chromax that I had on before.

Well, at least this part isn’t possible. You can’t make anything 8C colder by changing fan type. Maybe fan A vs no fans at all, but you don’t have 8C of coolant temp to loose. The Chromax NF-F12 has the same blade as industrial version and moves the same amount of air at the same speed. The motor is different, but that does not affect airflow. You might gain 1-1.5C in coolant reduction at 1500 vs 2000, but it would have to be in an extreme use scenario. You just don’t have the watts on a 3700x for that kind of difference.

You can try swapping the connectors on the splitter 1<->2. However, this is more characteristic of incompatible PWM tech than a wonky splitter. This behavior has been an issue on the 3000 PWM Industrial only. I used the 2000 rpm version in both F12 and A14 form for years on Corsair controllers as have many others, so it’s not clear if the Platinum PWM controller is different or there is a more basic reason.

I'll give that a try, but I suspect you're right about incompatible PWM.

Well, at least this part isn’t possible. You can’t make anything 8C colder by changing fan type. Maybe fan A vs no fans at all, but you don’t have 8C of coolant temp to loose. The Chromax NF-F12 has the same blade as industrial version and moves the same amount of air at the same speed. The motor is different, but that does not affect airflow. You might gain 1-1.5C in coolant reduction at 1500 vs 2000, but it would have to be in an extreme use scenario. You just don’t have the watts on a 3700x for that kind of difference.

I should have said CPU package temp. It went from about 68C to 58-60C under full load. Though the fans were not quiet, but now that I'm looking at it again, I see the issue.

I think you're right, something was off with my test.

Re-running my test now with the chromax fans and it looks like the other variable was the fan RPM.

I'd just been using the stock fan profiles in iCue and even under full load with prime95 and the chromax fans on the Extreme profile. The fans generally hang out around 600-800 RPM. The industrial fans were *only* turning on at 100%. So that's probably the real difference here.

If I switch to a custom profile with 100% fan RPM with the chromax fans, I see the CPU package temp go from 68-70C down to 58-61C.

This is as good as I was seeing with the industrials, so not sure if it's worth the trouble to figure out why they were not working.

Thanks for pointing out the flaw in my testing.

Perhaps try connection one of the ML fans that came with the kit or any other 4 pin PWM fan you have lying around to the splitter. You don't need to mount it. It would be good to verify the splitter works. A lot of us have been using the 2000 rpm PWM Industrials for a long time on multiple Corsair fan controllers. The Platinum is newer and I don't have one. I do not know if something was changed on the Platinum, if no one with a Platinum has tried the industrial series, or something else entirely. I do keep track of which fans do not run. Thus far it has only been the 3000 PWM Industrials, BeQuiet SW2 and SW3 PWM series, and the EK Vardar PWM. All of those are known for being "distinctive" in their PWM behavior. The 2000 PWM would be a surprise.

It is possible the CPU package (or core) temps were 8C different in your tests, but there would have to be other variables involved. Room/case temp is usually one, program load, prior heat retention... something. As far as the fans go, you should look at it on a strictly watts in/out kind of approach, which is most easily seen as coolant delta. 27C idle to 35C (level) when running Prime 95. I would expect your total coolant rise to be about 8C, so it would be impossible for any fan to be 8C better or even close. The difference between your coolant temp and that first peak CPU temp you hit when initiating the 100% load should be a fixed value vs voltage. So for your CPU, when you set it to 1.30v (or whatever) and initiate CPU-Z, the CPU temp should hit +38C above coolant temp (or some similar value) every time. That should be consistent and also allows you to calculate how much you can let the coolant temp rise before you cross a CPU temp you are not comfortable with.

Perhaps try connection one of the ML fans that came with the kit or any other 4 pin PWM fan you have lying around to the splitter. You don't need to mount it. It would be good to verify the splitter works. A lot of us have been using the 2000 rpm PWM Industrials for a long time on multiple Corsair fan controllers. The Platinum is newer and I don't have one. I do not know if something was changed on the Platinum, if no one with a Platinum has tried the industrial series, or something else entirely. I do keep track of which fans do not run. Thus far it has only been the 3000 PWM Industrials, BeQuiet SW2 and SW3 PWM series, and the EK Vardar PWM. All of those are known for being "distinctive" in their PWM behavior. The 2000 PWM would be a surprise.

I just tried what you suggest with one LL120 that came with the cooler, and a Noctua Industrial 2000. If I set a custom profile with the fan RPM set at various values. The Noctua will spin up, but it's RPMs seem to keep swinging up and down...

That led me to try a few different things.

With a custom profile, Fixed %, the Noctua fans won't turn on at all unless I set it to 100%.

However, Fixed RPM, they will spin up, even at the lowest RPM, 360. I know these fans have a minimum rotational speed of 450 RPM (+/1 20%).

I can actually connect only Noctua Industrials and they spin up when I set a Fixed RPM. But they won't hold a constant RPM. They swing all over the place.

See the RPMs here:

Anything else I should try?

It is possible the CPU package (or core) temps were 8C different in your tests, but there would have to be other variables involved. Room/case temp is usually one, program load, prior heat retention... something. As far as the fans go, you should look at it on a strictly watts in/out kind of approach, which is most easily seen as coolant delta. 27C idle to 35C (level) when running Prime 95. I would expect your total coolant rise to be about 8C, so it would be impossible for any fan to be 8C better or even close. The difference between your coolant temp and that first peak CPU temp you hit when initiating the 100% load should be a fixed value vs voltage. So for your CPU, when you set it to 1.30v (or whatever) and initiate CPU-Z, the CPU temp should hit +38C above coolant temp (or some similar value) every time. That should be consistent and also allows you to calculate how much you can let the coolant temp rise before you cross a CPU temp you are not comfortable with.

I'm pretty sure this was because I was comparing totally different fan RPMs. Max RPM with the industrials and quite low RPM previously. I wasn't looking closely at coolant temperature. I did let the test run for 10-20 minutes before considering the temperature stable.

But your point is well taken regarding coolant deltas. I'll take that into account if I setup some custom fan profiles.

Thanks.

That's interesting. I see you also have the SE white version and it's possible most people stick with the white LL fans for aesthetic reasons. This may not have come up before.

Do Custom Curves on the H100i Plat. SE run from RPM or PWM%? I seem to remember the Asetek based ones were PWM %, but don't know if the CoolIT OEM Platinum coolers use RPM or %. If RPM, the custom curve might still work. This aside, it does behave like a PWM incompatibility.

Do Custom Curves on the H100i Plat. SE run from RPM or PWM%? I seem to remember the Asetek based ones were PWM %, but don't know if the CoolIT OEM Platinum coolers use RPM or %. If RPM, the custom curve might still work. This aside, it does behave like a PWM incompatibility.

Looks like the custom curve is a PWM %.

I think I'll return these Noctua Industrials and just stick with the chromax ones.

I've also thought about sticking with the LL120s, but they are noticeably louder. I'm aiming to make this PC nearly silent, since it sits right on my desk...

Thanks for the help!