Question How Do I Configure My Fans To Make My CPU Run Cooler?

[catboy]

I built a new computer over the last week or so.

I am using an Antec Flux Pro case with both of the side panels currently removed, and all 6 of the stock fans are active.

I'm using a Noctua D15 G2 CPU cooler on an AMD 9800X3D CPU, and both of the CPU fans are active on the heatsink.

Over the past couple of days I've noticed then even when I only have a bunch of web browser tabs open and Word documents, and my computer is not doing anything else, often my CPU will go up to 52 degree Celsius.

Other times, it goes down to 40 degrees Celsius, but it doesn't seem to get much cooler than that.

I've left both of the sides panels off of my case because I have been doing work on the computer, but now my work is done, so soon I will be putting the side panels back onto the case. I don't know if that would make the temperatures better or worse.

I would like for my CPU be at a temperature of around 34 degrees Celsius while I am not doing anything other than surfing the internet and/or working with Word documents.

The UEFI of my AsRock motherboard allows me to set 5 temperatures per fan (including the CPU fans) and to set the % of the fan's possible power to use when it reaches the specified temperature.

So far as I've been adjusting these settings, my adjustments haven't worked at keeping my CPU in the 30's range while surfing the internet and using Word documents not doing anything else.

Can you please tell me how, exactly, I have to configure my fans in order to accomplish that?

Another thing I'm wondering about: shouldn't my Noctua D15 G2 cooler be performing better? Supposedly it's the best air cooler that is currently on the market, but yet, I'm not impressed by these temperatures on my CPU while using it.

Thank you.

 

[In2Photos]

You're not going to get the 9800X3D below 40C at idle. AMD CPUs tend to idle higher than Intel CPUs due to the chiplet design. This is normal and not a big deal. They also run hotter than older CPUs under load. This is also normal.

That being said, where are your fans placed on the case? I would opt for 3 on the front as intake, two on the top as exhaust and one on the back as exhaust.

You also could try undervolting the CPU to reduce power and temps slightly, but don't expect miracles.

 

[In2Photos]

Also, you can play around with various fans curve settings to achieve the desired noise/temperature. I tend to let my fans stay pretty slow to keep things quiet until the CPU gets in the 80s, then I start to ramp up the fans a little.

 

[catboy]

That being said, where are your fans placed on the case? I would opt for 3 on the front as intake, two on the top as exhaust and one on the back as exhaust.

My case fans are 6 140mms placed in their stock configuration.

That being:

3 Intakes seated vertically on the front of the case
2 fans seated horizontally, above the PSU, and below the graphics card area.
1 Rear Exhaust, seated vertically at the back of the case, in the same orientation as the CPU heatsink fans.

And then I have the two CPU fans on the heatsink in the configuration that Noctua recommends, in addition to the 6 case fans.

The case offers options to mount more fans on the top, but I'm not sure if I should do that, because when I read about that online, a lot of people say that a top Exhaust fan would conflict with the other fans, and therefore make my airflow worse, not better.

 

[In2Photos]

Watch this video. They likely tested different fan locations on thermals

 

[Paperdoc]

A couple of notes on the fans as installed now. You have six, but five of those (front 3 plus bottom 2) are intakes, and only one exhaust. You do need to add more exhaust fans (below). For now, check where the bottom intake fans are. I see in the case manual it is possible to mount them to the front of the PSU so the air they blow is NOT coming in though the PSU. The PSU cools itself.

Now, I suggest you do add TWO 140 mm fans in the TOP MID and REAR positions as exhaust fans. These will add air flow and balance intake versus exhaust somewhat better. The notes you have read about NOT using top fans usually are concerned with this factor: a fan at the top FRONT can "steal" air brought in by the top fan on the front panel and shoo it out so you get no benefit from that. But if you install two fans at middle and back of the top panel, you do NOT have this problem and you do get increased overall air flow.

Another note. I see the case comes with a fan and lighting HUB. Remember that modern fans with ARGB lights in their frames really are TWO devices in one unit. The fan and the lights are completely separate from each other, and each has its own power cord. Ignoring the CPU cooler fans, you will have 8 fans (if you add 2 more), but that Hub has five output ports for fan motors. (I believe that none of these fans has lights.) I suggest you buy a simple fan SPLITTER like this example

https://www.amazon.com/Pack-PWM-Fan-Splitter-Cable/dp/B09WZRQ5YV/ref=sr_1_1_sspa?crid=1MXPGDVMW4KV0&dib=eyJ2IjoiMSJ9.fP_L86GoighQZ83euUDDW34vzINQSzrnigrQcuslbH8gTctpfCWgk5D3qENqzrilC1SASyYyVYzX47foQ_nfdZj6oC11EAZsmNr4uNc7Wwh-QiZznA_BX5BaMznoJCjINe4zOWvGBkr9YwACpC0-Y637vYWLpgCt9SKj-7PwMqiBjGBjz3BYuFWC30IJsVatSS-yWeHIG23nzCKXeIAmMLpbd7xZay5isKtixBh3Anc.SBpQ0tU5EdjkBu7WGSJG55AwFWEawc0TsR_FmspoDIY&dib_tag=se&keywords=fan%2Bsplitter%2B4%2Bpin&qid=1740611223&sprefix=fan%2Bsplitter%2Caps%2C133&sr=8-1-spons&sp_csd=d2lkZ2V0TmFtZT1zcF9hdGY&th=1

That's a 3-pack of Splitters; each has four outputs for fans. NOTE that these items have only two types of "arms": one arm goes to a mobo fan header, and four of the other type are for plugging in fans. It does NOT have another "arm" that plugs into a power supply output connector. (The HUB included with your case DOES need a connection to power from the PSU, but this Splitter does not.) The limit on using a Splitter is that the total max amps drawn by all fans on the Splitter and its host header cannot exceed 1.0 A. Most fans you buy will have max amps ratings less that 0.2 A each - the fans supplied with your case have a spec of 0.12A normally, 0.18A peak. So you CAN plug THREE of your fans - I suggest the rear and two new top ones - into one Splitter that is connected to one mobo fan header, leaving the front 3 fans plus the bottom 2 on the case's Hub connected to another mobo fan header. In using the Splitter, notice that only ONE of its four ourput "arms" has all 4 pins in it. That is because the host mobo header can deal with the speed signal sent back to it from only one fan. So you must plug one fan into that 4-pin output so its speed can be sent back. The speeds of other fans on this Splitter will never be "seen" anywhere, but this does NOT affect ability to cotnrol their speeds. A simlar system is used by the Hub supplied with your case so that the speed of only one of its fans is sent to its host header.

Finally, ALL of the case fans should be connected to mobo SYS_FAN or CHA_FAN headers. In your case I suggest that you configure both headers you use for case fans identically. That type of header uses a temperature sensor on the mobo to guide it. The fans of your Noctua CPU cooler should be connected to the CPU_FAN header that uses a different temp sensor inside the CPU chip to guide it.

 

[mindless1]

Isn't that only a 120W TDP CPU? Even if it idles hotter than some, it still seems like that heatsink should keep it below 50C idling unless your fan curves are set too low for noise reduction, without having to reconfigure any of your case fans, unless they too, have a temp:RPM curve set too low and they're barely spinning.

Anyway, what thermal compound are you using and how much? I'm not going to suggest some exotic compound because I've never needed it for a mere 120W TDP CPU, but if you've put too much on or the heatsink isn't sitting quite right on it, then I'd try remounting it with less thermal compound.

Regardless, I wouldn't worry nearly as much about idle temps as I would about full load temps, which you did not mention.

 

[dlerious]

Which of the three D15 versions do you have? Noctua recommends standard or LBC for zen5

Which version of the NH-D15 G2 should I buy (LBC, standard or HBC)?

Our standard recommendation is the standard NH-D15 G2 because it’s the best allrounder and most versatile of the three versions: It provides the best results on LGA1851, AMD AM5 using the included offset mounting, and on LGA1700 CPUs when utilisi...

faqs.noctua.at

 

[catboy]

Which of the three D15 versions do you have? Noctua recommends standard or LBC for zen5

I have the standard version of D15 G2, set onto the -7mm offset holes on the mounting bars for AM5.

Anyway, what thermal compound are you using and how much?

I used the whole tube of the Noctua thermal paste that came with my D15 G2.

As for temperatures under load: I don't know that yet. I didn't want to game before I get my fans straightened out first, in hopes not to damage my CPU via overheating it.

Even if it idles hotter than some, it still seems like that heatsink should keep it below 50C idling unless your fan curves are set too low for noise reduction, without having to reconfigure any of your case fans, unless they too, have a temp:RPM curve set too low and they're barely spinning.

That's one of the main things that I'm trying to figure out. What, exactly should I set my UEFI fan settings to, in order to make sure that my CPU has ideal cooling, and stops being around 52 degrees Celsius as I'm doing nothing other than browsing the web with a couple of dozen or so tabs open?

 

[mindless1]

Whole tube? How big was the tube?

I'm guessing that was probably about 4X too much. If you are now out of thermal compound, I'd take a credit card and salvage about a pea sized blob, get rid of the rest, then put the pea sized blob on, spread out slightly on the middle, or the pressure of the heatsink will eventually do that, settling in to a lower temp over several thermal cycles.

However their heat spreader plates are known to be very flat (I realize, they have different profiles for different CPUs but in your case you have the standard one), so you might not even need as much as a pea sized blob. I'd start with less than that.

On the other hand, as stated previously, the main thing is the max load temp, and how much noise to accept to lower it. That heatsink should have no problem at all keeping a 120W TDP CPU cool enough if the case fans are moving even a modest amount of air through.

Do you have a high TDP video card? It would need to be using more power than the CPU, and not be rear-slot-bracket exhausting, for a single 140mm case fan to be a problem with that heatsink, unless the case fan(s) are throttled back to where they are barely spinning, but I can certainly appreciate doing that with multiple fans in the case, to reduce noise.

I think you need to focus on remounting the heatsink with less thermal paste first, see how that goes, and then look at your fan curves vs temperature.

I would set a fan curve to where, based on the case design and where you have placed it relative to where you are sitting to use the system, you cannot hear the fans at low load. I would keep decreasing the fan curve temperature threshold of temperature for fan RPM increase, so fan(s) spin up sooner, till you you can hear the fans at low load, then back it off from that until you can't hear them.

Otherwise, I'm again back to setting the fan curve to where it ramps up enough to not let the CPU get too hot. If not overclocking then I'd consider too hot to be over 70C, or if overclocking a bit lower than that. This is not only considering the max temp that the CPU manufacturer suggests but also that as CPU temp goes up with load, so does the motherboard CPU VRM power supply subcircuit, so that extra cooling for the CPU will cool the motherboard more as well. If you replace your system at shorter intervals than every 5 years or so, then it doesn't matter as much. Heat kills things over time. Obviously I am only generalizing but with still no report of overheating, I would not be looking to blow a hurricane through the system with associated noise and dust increase.

 

[BoomerD]

The WHOLE TUBE of Noctua TIM? That tube, if it's like this one that came with my Noctua cooler more than 10 years ago:



contains enough material to properly seat at least 10 coolers to CPUs.

By the way...did you use Noctua's AM5 thermal paste protector that they include with that cooler?

Thermal paste guard for AMD AM5​

When the mounting pressure of the cooling solution is applied, excess thermal paste will be squeezed outwards. With AM5 CPUs, this excess paste tends to accumulate in the cut-outs at the sides of the heatspreader and may become difficult to remove. Simple and risk-free to apply, the NA-TPG1 prevents this undesired phenomenon.

Also, which mounting did you use?

Offset mounting option for AMD AM5​

The NH-D15 G2 includes Noctua’s offset mounting bars for AM5 that make it possible to install the cooler shifted towards the south side of the socket by 7mm, thereby achieving better contact quality right above the CCD(s). This can help the LBC version to edge out another few tenths of a degree, enables the regular version to perform on par with the LBC version and puts the HBC version within close range. For detailed data, see this article. (article not found)

 

[catboy]

My GPU is a 2080.

Yes, I did put the paste guard for AM5 over my CPU, before I applied the thermal paste.

I am using the mounting bars for AM5 that came in the D15 G2 box, set onto the -7mm offset holes.

When I applied the thermal paste, I tried to follow the Noctua instructions, and put one dot in the middle, and then four smaller dots on the corners. That was my first set of squeezes.

However, my paste didn't end up coming out in the way how I thought it was going to, and how I wanted it to.

So I gave it a second set of squeezes to try to fix that problem, and apply the dots in accordance with those instructions.

And after that second set of squeezes, the tube was empty. It emptied much faster than I thought it would (but I'm not an veteran of applying thermal paste...I've done it a few previous times, many years ago...I haven't ever done it a lot, though).

Last night I used the AsRock UEFI to test my fans for the lowest possible speed they can run at.

Immediately after I did that, then my fans instantly became massively louder. I've have also read complaints from other people on the internet who said that happened to them too when they ran that same test with their AsRock UEFI.

My UEFI said that some of my case fans had a minimum power cycle of 63%, which didn't seem right to me.

And as far as I can tell, the AsRock's UEFI doesn't offer any way to undo minimum fan speed test.

So, in hopes to revert the massively louder fans, I pressed the CMOS reset button on the back of my case, and for a while, that really screwed up my system.

It didn't fully reset the CMOS (I could tell because it still showed the current date, but the date that my CMOS was set to when I first installed the motherboard as October or November 2024).

And all of my fans RPMs were being listed as 65535.

Then I did google searches about that, and people were saying it happened to them too, and they had to RMA their boards to ASRock.

I reset the CMOS a few more times, and eventually it worked to reset fully, and it showed me the 2024 date on my UEFI, and the 65535 RPM errors stopped appearing.

Do you guys know why that happened?

Does that stuff make any sense to you?

Do you know why AsRock's UEFI makes the fans significantly louder after doing a minimum fan speed test with it?

Do you know why AsRock does not offer any way to undo the results that it applies to the fans after doing that test? (other than clearing the CMOS to erase the test results)?

Can you guys please tell me exactly what settings I should input into my UEFI to control the fans in an ideal way?

Every time I look for guidance on the internet, including from Noctua itself, all I see are vague statements that don't help me at all, which say things like "there is no such thing as an ideal fan curve."

Well, I need numbers that I can practically input into my UEFI. Vague statements don't tell me how to do that. So with vague statements, I'm left guessing what the inputs should be, and I'd rather not have to guess, since my guesses are probably going to be wrong.

I wish someone would tell me the correct numbers, specifically, so that I could input them.

 

[Paperdoc]

A thought. Your tales say you DID use too much thermal paste. That SHOULD have produced excess of it squeezed out around the CPU cooler, but you do NOT report seeing that even after your second addition of paste. That makes me question whether the cooler was properly tightened down onto the CPU chip.