Silencing the 2U Ampere Server (Build Log 3)
Replacing the CPU cooler and Chassis Fans
I heard that these Dynatron W1s were much better at cooling the CPUs than the stock passive cooler that comes with the Asrock Mobo bundle from Newegg, so I went ahead and grabbed one. An active cooler, especially one that is designed to blow air from the front to back of the chassis, would allow me to use quieter chassis fans, resulting in both reduction in temps and noise.
The heatsink itself looks very similar to the stock heatsink that comes with the Asrock Mobo bundle, but that heatsink is slightly longer front-to-back, which doesn't provide enough clearance to place fans on the front or back of the heatsink.
The Dynatron W1 heatsink is shorter, but seams like the heatpipes are of much higher quality and there is enough clearance to fit a 60mm fan on both the front and back of the cooler.
I immediately noticed better temps, now idling around 45 degrees.
After adding a GPU, which meant a bit more heat generating components, I had to modify the setup a bit to improve temps a bit more:
- Swapped two of the 60mm chassis fans to 80mm Arctic P8 PWM fans - these are rated for higher static pressure than the 60mm Noctuas while still being able to run silent, but also able to ramp up to much higher RPMs. The remaining 2 fans cannot be swapped due to the front-IO daughterboard.
- Mounted (taped) one of the 60mm Noctuas to the exhaust side of the Dynatron cooler
With the GPU, the chassis is definitely a bit warmer now, but I've got it to a stable 48 degrees idle at 30% RPM, which is essentially silent in the grand scheme of things.
The issue though was not the front though... it was the back. 62dB idle. The damn PSUs.
The PSU noise problem
Like holy shit, I thought 62 dB was the worst it was going to get, and oh boy I was wrong. Seattle started to get really warm this week and ambient temperature was rising. And that was enough to have these PSUs turbo-boost their fans to 100%, and it started to become a real jet engine. I didn't measure the dBa, but it felt 5x louder than idle.
So this problem has just became 10000x more urgent, given that my rack lives in my office, and there is no way I'll be able to deal with the noise 24/7. I had to start looking for options.
It would be great if I can just replace the entire PSU unit with a consumer grade SFX PSU, but unfortunately the chassis just does not have the space for it, even though there are many 2U chassis out there that are designed around SFX PSUs. My chassis does not have enough room for such PSU due to how compactly it is designed to support a large GPU.
I was exploring two possibilities:
- A replacement CRPS PSU that is quiet.
- A TFX PSU, specifically the Silverstone TX700
After almost a full 2 days of research, I decided that the TX700 is the most realistic option, and immediately clicked on the "Order Now" button. The TX700 is cooled by an 80mm fan, which should be more quiet than any 2x40mm CRPS PSUs.
Below are size comparisons:
I had to 3D print some brackets so that I can mount the TFX PSU in the chassis, and I was quite surprised that my measurements and 3D prints went perfectly in a single attempt. I'm no expert and I always need multiple iterations, but this time the stars just aligned.
And lastly, the cable management!
But how about the noise? Well, all I'll say is... "Mission Accomplished".
It's also 47dB when measured with the chassis closed and racked up. Given that there are no more 40mm fan whine, the overall noise is indistinguishable from the rest of the rack mounted equipment. The loudest thing in my rack at this point is my raspberry pi cluster which uses tiny 40mm fans, which testifies how quiet the rack has become.
The beast has finally been tamed, and I'm really happy with how this server turned out. The only thing remaining now is to grab SSDs and setup ZFS, but the 8TB SATA SSD drives that I was eyeing are all sold out for some reason, so I'm just waiting for them to get back in stock.
