Anyone tried adding 2x Noctua 92mm slimfans on top of the D4 v1 externally? Would this improve any temps? I plan to mount them either by magnets or doublesided tape, will share results + pics shortly!
I did some thermal testing just now as I received the magnets to mount my two internal NF-A4x20s, and I also have a spare NF-9x14 (not two though). See the imgur album below.
The system:
Intel Core i5-4560S with Noctua NH-L9i, Sapphire Radeon RX 570 ITX, custom 12V PSU. The PSU has an NF-A4x20 as an exhaust at the lower back of the case, shown as "Chassis 1" in HWinfo.
The configurations:
Everything stock
CPU stock, GPU +50% power limit
Fans set to various system curves; keep an eye on both CPU and GPU clocks
and temperatures
and fan speeds. This is not a variable-controlled test.
The tests: Combined Prime95 Small FFTs + FurMark. Yes, this is wildly unrealistic, worst-case-scenario testing. The GPU sticks to its power limit though, so it's realistic in its way.
The setups:
Base: Just the cooler + PSU fans.
My future setup: base + 2x NF-A4x20 mounted to the inside top front of the case with magnets, oriented as exhaust (pulling air upwards) (GPU side is a tight squeeze, but it fits).
The 92mm: Base + 1x NF-A9x14 mounted externally, oriented as an exhaust (pulling air upwards), powered from a 12V USB-C adapter to not have to remove any side panels.
Results:
Result notes: The NF-A9x14 is the coolest of the three setups, but also the noisiest by far. The issue is turbulence against the side panel, as the noise disappears almost entirely if the fan is lifted just a few mm from the panel. See the video at the end of the gallery for a noise demonstratio (sorry for the garbage video quality, it's dark here - but it's the audio that matters). I could also feel a dramatic increase in airflow as the fan was lifted. Most of this likely came in from around the sides, but this should still improve airflow around and through the case, and a spaced-out frame/bracket could focus airflow more.
The last image in the gallery shows the thermal results of a hacked-together noise dampening solution: propping up the fan on a pair of chopsticks. This drastically improved noise, even if the A9x14 at high speed is still the noisiest part of the system.
The N4x20s are inaudible over the GPU fan even at 5000rpm, which I find very surprising. There is also a very significant amount of heat exhausted by these fans, as you can see they manage to cool the GPU.
Solutions ranked after my tastes:
#1: Dual internal NF-A4x20s. The best combination of simplicity, noise, size and performance.
#2: External NF-A9x14 with some sort of spaced out mounting. Maybe a 3D printed bracket? It would increase the volume of the case and look iffy, but work.
#3: No extra fans. Works okay at these power levels.
#4: External NF-A9x14 with no spacing. It's just too loud.
