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Quest for a Silent PC

Posted by inder on April 2, 2005 at 2:25 PM PST

Is your computer too loud for you? Mine was, and it finally drove me to do some research on the Web about how to build a silent PC that is powerful as well. In this blog, I share my experiences in this quest.

Here are some things that affect the noise that your PC generates:

  • CPU Fan: Faster the CPU gets, more heat it generates which needs a cooling system that employes faster fans, which results in more noise. One popular option is to go for under-powered processors such as Via C3 that can be cooled without fans. However, I was not willing to make this compromise. The other option is to go for a CPU that runs at a lower clock speed. Athlon64 is a better choice here than Intel P4 since it offers similar performance at a much lower clock speed. I choose Athlon64 3000+ which comes in two types: socket 754, or socket 939. Socket 754 processor is made with 130nm fabrication process and runs at 2.0 GHz, and socket 939 processor is made with the 90nm process and runs at 1.8GHz. The socket 939 processor has lower power consumption and hence was the one I chose. Socket 939 was a little more expensive but socket 939 motherboards supports dual channel memory, and PCI-express which are important for performance and future upgrading.
  • Case Fans: These are among the biggest source of noise. The strategy for reducing noise here is to use a bigger fan (120mm) which rotates at lower speeds. You should also try to reduce the number of fans that you have in the system.
  • Fan on the Graphics card: Dont forget this little beast. Usually, the graphics cards have small fans, and the smaller fans need to rotate at higher speeds (which results in louder noise) to achieve the same cooling. In my previous system, this was the biggest source of noise since the fan on my ATI Radeon 8500 LE graphics card had gone bad. I quietened it by doing some hardware modifications. I removed the fan and its tiny heatsink, and replaced it with an old CPU heatsink that was lying around. This ate up the PCI slot next to the AGP slot, but the card was silent because it was fanless. You can do the same thing, however, keep in mind the cooling requirements of your card. I was able to cool my card with a better heatsink, but a more powerful card may need something like the Zalman passive cooling systems. Eventually, I went for a motherboard integrated graphics and, somewhat surprisingly, it was actually faster than my Radeon 8500 LE.
  • Power supply fan: Since the power supply fans are usually smaller in size, they can be noisy. I wanted to use a fanless power supply such as Thermaltake W0050. However, its reviews were less than stellar.
    So I settled for a power supply that automatically reduce the fan speed based on its cooling requirements. If you have lots of components in the system each of which require power, a lot of heat will get generated in the power supply, and hence it will need to run its fans at a high speed. Get rid of the extra hard disks, CD/DVD drives, PCI cards, and even graphics card if possible. Fewer components also help create a good airflow in the case.

  • Choice of Motherboard: The choice of motherboard is important because a motherboard with lots of integrated features can save you lots of additional components. I choose MSI RS480M2-IL motherboard that provides integrated ATI Radeon X200 graphics card, IEEE1394, and 8 USB ports. This helped me avoid a graphics card, a PCI card for IEE1394, and a PCI card for extra USB ports. It also provides 5.1 channel audio which was adequate for PC use.
  • PC Case: A PC case can also be a source of noise depending on the kind of fans it employs, and how it tries to reduce the vibration noise. It is also better to go for a bigger sized case to aid the airflow. I chose Antec Sonata which is at least designed with the goal of reducing noise. It is not the best option out there, but it was the best value for the money. It comes with a 120mm case fan, a smart power supply, and other vibration dampening measures. I guess what I really drooling about was Zalman TNN 500F but it was way more than what I wanted to spend.
  • CPU Cooler: Typically, the heatsink and the fans that come with a Boxed CPU are not of very high quality and the fans are somewhat noisy. I reduced this noise by going with a fanless solution. I chose SilverStone Nitrogen NT01 v2.0 Heatpipe CPU Heatsink. This could handle the Athlon64 3000+ well, but the CPU temperature was sometimes higher than what I expected. So, I added a low-noise 60mm Vantec ThermoFlow Adjustable Speed fan. I am not sure if using Nitrogen NT01 was a good decision, a Zalman 120mm CPU cooler might have been equally effective and cheaper.
  • Hard disk: Hard disks that go into the desktop PCs are typically very loud. The faster the rotational speed of the disk, louder it gets. The 10,000 RPM disks are the worst, so avoid raptors, cheetahs, and the likes. I chose a 7200 RPM disk with an 8MB buffer. I think it is also good to routinely run the defragmenter on the disks since that reduces the average number of seeks during daily use. Usually, the seek noise of disks is quite loud. Also, go for a single bigger disk than multiple smaller disks. This will not only reduce the number of sources of noise, but will also reduce the cooling requirements since hard disks generate a fair amount of heat. I agree that smaller multiple disks can be setup in a RAID 0 (or 0+1) array for higher performance but this study claims that RAID 0 offers almost no performance benefits in a desktop system.
  • DVD/CD Drives: Some of these drives (especially the cheap ones) can be very noisy. But fortunately, that happens only when the system is accessing the drives. Check the dB rating for the drive that you are buying. Also, make the hard disk as the primary boot device in the BIOS since that will eliminate an extra spin (and the delay in booting) when the system boots up.
  • Floppy disk: Disable floppy seek at boot in BIOS to get rid of the annoying seek noise. This will also help the PC boot a little faster.
  • Rounded cables: Use rounded cables instead of the regular flat cables for hard disk, DVD/CD drives and floppy drives. It helps the airflow in the PC case which results in better cooling, and hence lower fan speed.