Cooling

Cooling warrants specific consideration, whether you’re building for low noise or not. If you’re on a tight budget, you’ll probably have to make do with the cooling provided with your chassis and power supply for general airflow. We’ve also recommended buying a retail CPU in our budget PC, as this comes with a stock cooler for just a few pounds more than the bare, OEM version of the CPU.

But this setup will provide neither the quietest nor the most efficient option around. These two actually go hand in hand, as a highly efficient cooling system is also likely to be quieter. Spinning fans are what make the most noise, so a design with greater heat dissipation capability will run fans more slowly and therefore more quietly.

A basic rule of thumb is “larger is quieter”, but bearings and overall design can have an effect, too. If your chassis has noisy case fans, replacing them with quieter versions won’t be hideously expensive – less than £10 apiece. The figures to look out for are airflow in CFM (cubic feet per minute) and noise level in dBA: you want the largest for the former and the lowest for the latter. Also, make sure the fans will actually fit. Some PC cases have spaces capable of accommodating up to 120mm fans, but are supplied with 92mm or even 80mm ones as standard. Swapping these out for larger, silent-running models can have a very beneficial effect on system noise and ambient temperature.

However, we’ve already specified cases for our silent and gaming PCs that come with high-quality fans as standard. This leaves us with the cooling for the processor to choose. For Intel LGA775 processors, Arctic Cooling’s Freezer 7 Pro (www.arctic-cooling.com) remains a top choice on virtually every level. Not only is it very efficient, it’s cheap, too, at around £12. To cap it all off, it fits in the regular LGA775 fastenings. Many premium high-performance coolers require custom backplates, forcing you to remove your motherboard to fit them.

However, we wanted the very quietest, most efficient cooling available in our silent system, so opted for the ZEROtherm Nirvana NV 120 instead. This will keep even a top-end processor cool at its lowest fan-speed setting.

Since our gaming PC chassis has a window to show off its powerful internals, we wanted a cooler that looked the part. So we opted for Zalman’s CNPS9700 NT instead. It’s even more efficient than the Arctic Cooling, particularly with its fan on full. With blue LEDs, it will grace a visible PC interior with style.

We could also swap the cooling on the graphics card for a quieter version. Arctic Cooling provides a range of options for virtually any graphics card, with its latest Accelero range supporting the current top models from ATi and Nvidia. But we’ve already chosen passively cooled graphics in our silent PC, and you can’t get quieter than that!

The ultimate in cooling is refrigeration, but it’s noisy and primarily aimed at heavyweight overclocking. The most extreme option we’d recommend for a regular runner is water cooling. It’s often complex to install, but you can also buy pre-filled systems such as Swiftech’s H20 120 Compact (£75 from www.chillblast.com). Simply attach the water block to the CPU and install the radiator over a rear-facing 120mm fan outlet.

Most water cooling requires custom tube fitting and water priming, and is generally aimed at overclocking. But Zalman’s Reserator1, now in its V2 guise (£136 from www.quietpc.com), provides completely passive processor, graphics and North bridge cooling. However, it isn’t powerful enough to dissipate heat from high-end quad-core CPUs and powerful graphics cards. Zalman’s Reserator XT can, but at the expense of a 140mm fan. Although it’s still very quiet, at £229 the XT only justifies its price if you plan on some fierce overclocking.