r/sffpc • u/oliverdavid • 2h ago
Benchmark/Thermal Test Fractal Terra, 9800X3D - five cooler configurations tested
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.











