Silent PC with No Moving Parts

Do-It-Yourself Systems | The Silent Front
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Silent PC with No Moving Parts

A PC without any moving parts has been the Holy Grail of Silent Computing Enthusiasts for years. It's a quest that has led some individuals to fabricate their own cases, massive heatsinks turned inside out, with the components bolted inside them. The Zalman TNN 500 case was the most ambitious commercial realization of this concept, but it is now discontinued, probably due to high cost of production and shipping, low sales volume, and possible reliability issues with the built-in fanless power supply. We've never really been that fond of the fanless concept, simply because a small amount of forced airflow from a good quality fan is essentially inaudible in almost all environments, and its cooling superiority with a good heatsink easily beats even the massive TNN 500. There are also many components other than the CPU or GPU, such as the VRMs on the motherboard, which are best with some airflow for cooling under load.

Still, in special cases, a completely noiseless computer can be useful, perhaps even necessary. Such is the case with SPCR's anechoic chamber, built last summer. The ambient noise level in the chamber is 10-11 dBA, low enough that with the right audio equipment, the noise level of any computer component can be measured and analyzed at standard 1m distance. Such equipment is indeed in place, and the audio analysis equipment can actually measure down to about 9 dBA, below the ambient level of the chamber.

In the past, our carefully built fan-cooled computers were quiet enough to be below the ambient level of the lab most of the time. Now, in the anechoic chamber, these same computers register some 15~18 dBA@1m, high enough to interfere with the quietest components and computers we've tested. We made do without a computer in the chamber for many months, but increasingly, the lack of a PC in the room became too limiting. Something had to be done. Ideally, we wanted an open-bench system with instant access to all motherboard and power supply connections for quick and easy setup with peripheral equipment or changes on the fly. This meant no component can make any noise, as it really cannot be encased.

The main noise sources in a PC can be divided into two categories: Fans and hard disk drives. There are two others, electronic component noise (such as buzzing from coils and capacitors) and optical drives, but both can be disregarded here. The former is usually at too low a level to be significant or occurs only under very high load, which would not apply with our lab PC, and the other is a component we do not use except to install software. Fans can be eliminated by using a low power CPU with a big passive heatsink, and a fanless power supply. Both Silverstone (Etasis) and Fortron-Source fanless PSUs have proven to be quiet and reliable. The GPU is not an issue here, as we'd be using onboard video.

The hard drive, until recently, tended to set the baseline noise level below which a PC could not go. Yes, there are ways to encase the drive and float it so its mechanical spinning does not translate into audible noise, but these methods make the drive hard to access, and they tend to increase the likelihood of failure. The hard drive has traditionally been more fallible than other components, anyway, despite being the most essential, holding both the operating system and precious data. A solid state drive is the obvious solution, but the cost was prohibitive... until recently.

The decline in prices and improvements in the performance of solid state drives over the past year or two have not gone unnoticed at SPCR. We've been playing with Intel X80-M SSDs for the past six months, and following the trials and tribulations encountered by both users and reviewers with the issue of SSD stutter, their single biggest, most common, sometimes impossible to ignore flaw. Anand of Anandtech has written some massive but insightful reports on this issue (links to Anand's article on SSDs, take 1 and take 2), and as of this date, only three more-or-less affordable SSD lines do not suffer from stutter. The three are Intel, Samsung and OCZ Vertex. Given the usual pricing of these SSDs, it was a shock to discover in March an online store called offering Samsung 64GB and 32GB SSDs in 2.5" SATA form factor for $199 and $139. They were probably overstock items from some corporate OEM order. The Lenovo X300 laptop I recently acquired has a 1.8" 64GB Samsung SSD that's not quite as speedy as I'd hoped, but at such low prices, the offers were irresistible. If the performance was right, the 32GB model would be perfect for a modest low power, open test bed in the anechoic chamber.

Today, the OCZ Vertex SSDs are priced very similarly to the Samsung SSDs I purchased. They are probably better performers. But, given the title of this article, you already know that the Samsung SSDs proved to be fine performers. The 32GB model was used in our first lab PC without any moving parts. The system is perfect for our needs, modest, consuming very low power, and completely noiseless. It is used for hard drive testing, both performance and acoustics, as well as for power supply testing. In the latter role, it runs the digital oscilloscope used to measure AC ripple on the power supplies, and the various spreadsheets used to tabulate power data. At the same time, we use screen capture and other imaging software for those reviews. It will also be used in fan testing.

It doesn't look like much, but it is utterly silent. There are no moving parts except for the floppy; even that's silent once the Hitachi Feature Tool HDD utility is loaded.

Silent SPCR Lab PC Components

Most of the components were on hand, chosen mostly for low power (and low heat) and suitability to the task.

  • Asus M2NPV-VM - older AM2 socket nVidia 6150 chipset micro-ATX motherboard
  • AMD Sempron LE-1300 - modest single core 45W processor, 2.3GHz, 512KB L2 Cache
  • Scythe Orochi - massive heatsink with mediocre mounting not recommended except when motherboard is parallel to the ground as above
  • Corsair CM2X1024-6400 - single stick of 1GB 800 MHz DDRAM
  • Silverstone ST45NF - fanless power supply, overkill for the system but it was on hand and not engaged.
  • Samsung Enterprise SSD MCBQE32G5MPP-0VA - 32GB 2.5" SATA/300 SLC Solid State Drive
  • Mitsumi floppy drive
  • Generic USB wireless IEEE 802.11g adapter

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