Danny Yee >> Tech notes

Building a Quiet Computer

My partner Camilla needed a new computer and wanted something quiet. So with much reading of Silent PC Review (SPCR) and advice from Steven and Pete, I designed a system. The constraints were that it had to fit up to four disk drives, as well as an optical drive, that on-motherboard graphics were probably ok but a high-end video card might be needed at some point, and that it could be running cpu-intensive scientific computation for weeks or even months on end.

Components and Planning

The case was the big decision. It ended up as a pick between the Antec Solo and the Antec Mini P180. The Mini is smaller and has a separate compartment for the power supply, but is also overfanned (with a huge 200mm top fan that will be hard to replace or swap out) and lacks the hard drive suspension option that comes with the Solo. But I figured that if necessary I could take out the 200mm fan and have the same fan config as the Solo, and I could always improvise hard drive suspension myself.

I went with the Antec Neo HE power supply because of its "through flow" arrangement, with the vents behind rather than below. This fits the layout of the Mini P180 vents. Antec claims the Neo HE 430 runs at 18dBA and SPCR reports "The reported 20 dBA@1m was actually so close to the ambient level in our lab that it is difficult to judge whether it would measure less in a quieter room". In a separate chamber with a dedicated bottom vent, this power supply should be "out of the equation" as far as noise goes, at least up to 150 watts or so. It also has modular cabling, allowing me to keep the case clutter to a minimum.

A fanless heatsink is an obvious measure to avoid noise. And there had to be some positives to having that huge 200mm fan directly above the CPU! Here I just took the highest SPCR rated heatsink designed for use without a fan, namely the Thermalright HR-01-PLUS. With some searching, I found a forum post from someone using one of these in a Mini P180, to confirm that it would fit.

The CPU was picked for power and performance, and the motherboard was picked for the µATX form factor, the ability to take 16GB of memory, and the onboard graphics. The disk drives are reasonably quiet; I used drives from different manufacturers to reduce the risk of hardware failure taking out the RAID-1 array.


All the components were sourced from IJK, except for the NeoHE power supply which came from Australian Computer Online.


The Mini P180 case is really nicely engineered.

The modular power supply and the ability to run cables behind the motherboard allowed me to keep clutter right down. The final system has pretty much unimpeded air flow from the top front vent across the memory to the CPU heatsink and the exhaust fans behind and above that.

The most difficult part of the build was fitting the backplate around the motherboard ports. The backplate (both the one that came with the motherboard and a generic one that came with the case) are crappy, poorly-fitting thin metal, probably the least attractive and least robust component in the entire system.

I went into the BIOS and made the obvious changes: removed the floppy, changed USB to "full speed" instead of "hi speed", set the SATA controller to AHCI, enabled ACPI 2.0, set the CPU fan to None to stop complains on boot about it being missing.

Performance and Noise

When idling at room temperature (from 20 to 25), the CPU is at room temperature, but the motherboard is 15 degrees hotter! But apparently that's due to the location of the sensor. So maybe I will move the back fan to the CPU fan connector.

The case isn't silent, but you have to get pretty close to hear anything — the big 200mm fan at 400rpm — and even then the ambient noise is much more prominent. When I was rsyncing the files from the old computer to the new one, the former was louder, over 5 metres away in another room, than the latter, right in front of me! And when I was listening to it in its final location, late at night, I noticed a nasty hum from the stereo system (even turned off) which hadn't been audible before at all.

Stress-testing the CPU - running two burnP6 processes for ten minutes - pushed the CPU temperature up to 37.5 and didn't change the motherboard temperature! That was at a room temperature of 23, but I'm reasonably confident the system will survive if it goes to 40+ (which can happen in Sydney in summer).

Tech notes << Danny Yee