Building a Quiet PC
When the first version of Windows Media Center was released in summer 2003, I decided it was time to build my first home theater PC. After I placed it in the living room, I realized I had made a terrible mistake: I had to turn the volume up to 11 just to drown out the noise of the HTPC! I couldn't believe how loud it was! For the next few months, I immersed myself in the world of silent PC enthusiasts. I must have reconfigured that system a dozen times to reduce the noise.
Now every PC I build is optimized for performance and low noise from the very beginning.
Anyone can build a high-powered rig that sounds like a jet taking off. Building a high-powered rig that's so quiet your wife can't tell when it's turned on or off-- now that's an accomplishment! It's a bona-fide engineering challenge.
In the process, I've learned quite a few things about building quiet PCs. I'd like to share them with you, so you can avoid making the mistakes I did.
- The easiest way to build a quiet PC is to start with components that run cool. It's as fundamental as the first law of thermodynamics: heat has to be exhausted from the system; more heat equals more noise. If you truly want a quiet system, start with cool running components. The three components that generate the most heat in your system are..
- video card
- power supply
.. in that order. Select these items very carefully, because they will account for 90 percent of the heat and noise generated inside your computer. Research how many watts of power each will draw when idle; when normally loaded; and when fully loaded.
And don't underestimate the importance of the power supply; it's the heart of your system, and it can be the source of serious stability, noise, and heat woes if you pick a clunker. The very best power supplies are only about 85% efficient, which means they're still dumping 15% of the total power draw back into your case as waste heat.
One of the most useful noise diagnostics is to stop every fan in the system, one by one, using your Mark I finger. Repeat this a few times, listening closely to hear the difference with each fan stopped. Then try to eliminate or slow down the noisiest fan. Don't forget to test your video cards and motherboard fans while you're at it; these tend to be particularly noisy due to their small size. And remember, kids, always stop fans by touching them in the center, not in those whirling blades!
The Zalman 56 Ohm resistor is a less expensive option if you don't need precise speed control.
- The current top dogs for CPU cooling efficiency are tall heatpipe stack designs such as the Thermalright Ultra-120 and the Scythe Ninja.
- The current top dogs for VGA cooling efficiency are copper heatpipe designs, such as the Arctic Cooling Accelero X1 and the Zalman VF900-CU.
- Consider replacing any small fan and heatsink combinations -- such as the ones commonly found on motherboards -- with larger, passive coolers. Two great options are the Zalman NB47J and the newer, flower style Zalman NBF47.
Note that aftermarket coolers tend to be quite a bit larger than stock coolers; measure to make sure they'll fit in your system before buying.
As such, the first order of business here is to dampen the drives -- make absolutely sure there is a soft material of some kind between the hard drive and your PC's case. Some people improvise bungee suspension slings, some people use foam or sorbothane, some people put them in dampening enclosures. Whatever you do, always avoid metal-to-metal contact between a hard drive and the case.
The truly hardcore use 2.5" laptop hard drives, which are even quieter, but they also have significant performance and price penalties over standard 3.5" desktop drives.
That said, noise reduction materials can help take the edge off the last remaining bit of noise in a system. For PC builds, I like pax.mate and generic eggcrate foam. You can see pictures of both materials in action in this SilentPCReview thread documenting a LAN party system I built in summer 2004. But they should always be a final, finishing step.
I'm ashamed to admit that I have something of an eggcrate foam fetish. In addition to wedging it inside my systems wherever it'll fit, I regularly put cardboard-mounted panels of the eggcrate foam behind my PCs to reduce the reflected noise from the rear exhaust fans. If your PC is under a desk, fitting eggcrate foam along the undersides of the desk can be surprisingly effective, too.
Passive cooling setups are an order of magnitude more difficult to cool: they require a tricky balance of careful construction, natural convective airflow, and setup tweaking. You can achieve 90 percent of the results you'd get with completely passive cooling using a few nearly-silent, slow-moving fans-- at a fraction of the effort and risk!
I can't emphasize enough that the best way to quiet your PC is to begin with the right parts. If you're really serious about silence, ensure that you have..
- CPUs and video cards that run cool
- a quiet, efficient power supply
- hard drives that run relatively quiet as shipped
Always try to deal with the source of the noise first. Beyond that, following the few tips I outlined above will eventually get you to near-complete silence-- or at least to below-ambient noise level, which is pretty much the same thing.