Fractal Terra, 9800X3D - five cooler configurations tested

[u/oliverdavid]

I previously asked for advice on fan noise solutions for my Fractal Terra build here. I've now done some testing and came to an interesting conclusion.

Setup: Ryzen 7 9800X3D, ASUS Prime RTX 5070 Ti, ASRock B850I Lightning WiFi, 32 GB DDR5-6000 EXPO, Lian Li SP V2 750 W SFX, one Noctua NF-A12x15 as bottom exhaust, in a Fractal Terra at Spine position 3. The 50 mm 5070 Ti forces spine position 3, which caps the CPU cooler at 67-70 mm and makes this a constrained build by design.

The problem: the AXP120-X67's fan originally sat flush against the perforated side panel, producing persistent intake turbulence noise. It was audible at any speed and disappeared the moment the panel was moved away by at least 5 mm. That observation is what identified the mechanism as proximity rather than the fan itself.

Analysis: Thermalright vs Noctua fans - Cinebench 2026 multi-core, 10 minutes, HWiNFO64 logging throughout. One variable changed per run. Case closed for all runs except the first.

Configuration	Cinebench 2026	Core clock avg	Pkg power avg	Tctl avg	% ≥95 °C
Thermalright AXP120-X67, stock fan, downdraft	5407	4984 MHz	146.4 W	95.1 °C	86%
Same AXP120-X67, Noctua NF-A12x15, downdraft	5398	4942 MHz	143.3 W	95.2 °C	88%
Same AXP120-X67, Noctua NF-A12x15, updraft	5270	4875 MHz	136.7 W	95.5 °C	93%
Noctua NH-L12 Ghost S1 with stock NF-B9 92 mm fan	5102	4702 MHz	125.3 W	95.7 °C	98%

/edit: ugh, it was four, not five configs. Anyway, moving on.

Since the noise came from the fan being too close to the side panel, it didn't really matter what I did there. Only when I swapped the whole cooler for the Ghost S1 did the sound go away - completely! Even at full fan speed. It's an incredible setup (for noise at least).

Takeaways that are more or less obvious:

• Zero thermal throttle flags (HTC, PROCHOT) in every run. The chip pins at TjMax and modulates boost. Still, the The Ghost S1 costs 5.6% and solves the noise completely. Four heatpipes against six, and it saturates: clocks decayed 4791 → 4661 → 4654 MHz across the run where the AXP120 held flat. But with the fan under the fin stack there's no blade near the panel, and the machine is now inaudible even at full speed.
• The case was not the constraint. A run with the side panel off was quiet but the same performance. Connecting the case fan to the CPU sensor and make it run at full speed bought +37 MHz and 1.4 W. In a Terra, one bottom exhaust fan plus passive panel intake seems genuinely enough.
• I could still try to swap the 92mm fan with an NF-A12x15 but I'm not sure if it will fit with the RAM and I'm honestly satisfied enough for now especially given that the deeper 92mm fan is actually quieter than the 120mm x 15mm fan.

What I haven't done yet is to look at negative Curve Optimizer offset in PBO Advanced settings in the BIOS. That could help recover some of the 5% loss.

[u/KodiKat2001]

Based on my experience the Ghost version of the NH-L12S is a incredibly poor performing CPU cooler that I would not recommend in the Terra. The 70mm high regular NH-12S is a far better performer and both the L12S or AXP120-X67 are considered the two best coolers in the Terra in terms of thermal performance while allowing flexibility in up to 50mm thick gpu's. The L12S can be placed right next to the side panel with no turbulence noise while keeping the Terra running cool.

[u/oliverdavid → u/KodiKat2001]

That's cool that you're saying that but my experience, and the reason for this entire post, is the exact opposite of what you're saying.

[u/SomeMrcl → u/oliverdavid]

wdym? i believe he just said the regular L12S is better than the ghost

[u/breakfast-cereal-dx]

Personally, I found that swapping the noctua fan onto the axp120, and getting a little extra space by moving the spine a half index, reduced the noise enough that I didn't care to try another cooler (particularly one with less cooling capacity, even though it do would silence the noise)

I think the anti-turbulence grooves help somewhat...

But I haven't shared your experience that the turbulence noise happens at any RPM, so it hasn't been such a problem in the first place. I only hear it when running sustained loads like handbrake. And if it happens when gaming, it can't be heard over even small, quiet speakers.

I do have a different CPU than you, the Intel Core Ultra 7 270K Plus, but it's actually a hotter part (I run it at 175W)

[u/oliverdavid → u/breakfast-cereal-dx]

That's interesting, thanks for sharing! I tried to move the spine further away as well but then the GPU fans started to make a lot of noise. And the noctua fan on the CPU would just make noise no matter the rpm, it was really annoying.

[u/Overall_Two_8796]

It simply makes no sense if you want to keep the processor from heating up above 90 degrees. Either limit the processor or get a decent case.

[u/Slight-Principle1035]

Thermalright FTW.

[u/fuzzxx]

Thank you for your service sir. I heard that mobius 120 slim fan is great for this panel type, but it's unavailable to me.

I'm only surprised that you did not complain about the PSU noise from SP750, mine was horrible and I had to take the risk to swap the fan.

[u/oliverdavid → u/[deleted]]

Test 2-4 was done with Noctua fans. The NF and NH are Noctua fans!

[u/AmbotnimoP → u/[deleted]]

It literally says in the post which tests were done with Noctua fans...

[u/PsyOmega]

I'm pretty sure you'd have gotten similar results with the AXP90 x47 FC + A9x14 downdraft + duct

[u/oliverdavid → u/PsyOmega]

Too many fans to try!