Reducing HTPC noise

Ok, so you’ve built your HTPC (or you’re at an advanced planning stage) and you’re starting to worry about how noisy it is now it’s sitting under your TV. Well there’s no need to panic, many things can be done cheaply and I’ll try to give you a flavour of some of the options you have. Obviously if you want to you can buy silent HTPC cases with fanless CPU and case cooling systems for as ‘little’ as £400! However that’s not what this article is aimed at and you should be able to get good results for minimal outlay.

I firmly believe that you can get a HTPC quiet without spending much money, sometimes without spending anything extra! For example, the MSI K7N2GM2-ILSR socket A motherboard has brilliant bios settings that slow the case and CPU fans down to a crawl unless it gets close to a set temperature (my system temp is set to speed the case fans up when the temp hits 45C and the CPU fans from 55C). Unfortunately this board seems to no longer be in production and I’ve never seen anything similar (why MSI?).

One issue that you obviously have to consider before applying some of these techniques is a realisation that your system will still produce heat. Masking the noise and/or reducing airflow can leave that heat in the system and shorten some of the components lifespan, so be reasonable.

The majority of noise from your HTPC is likely to be from the fans. This includes not only the power supply (PSU), CPU and system (case) fans but also a graphics card fan (unless you’ve got a fan-less version). Quietening these down means your DVD/CD and hard drive(s) are likely to be noisier by comparison, something which I’ll cover at the end of this article.

On the case fan front there are a few options, some of which can be used together. Firstly a better quality fan may be quieter. For example, SilenX do a range of differently rated case fans. Their ratings relate to both fan speed/air flow and noise levels. These will cost in the region of £10 – £15 each. There are other makes available that do the same thing. In my view it’s always worth while getting a 3 wire fan (the 3rd wire is used variably to control fan speed in a suitable system).

In case this isn’t within budget or it doesn’t produce good enough results the concept of fan volt modding ( see articles on the web) is an excellent one to consider (at your own risk). However if you want the safer option you can buy pre-made resistor cables (often branded Zalman) that do the same job, either altering the fan voltage down to 7 or 5 volts. These usually cost £2-£3 each. They work in a similar way to the famous Zalman fanmate but without the variable speed control. However you’ll often find that when used with a 3 pin fan the motherboard raises and lowers the fan speed even with the resistor cable. If a Zalman fanmate interests you that’s likely to be in the region of £7.

One invaluable component to consider using in conjunction with the Zalman resistor or fanmate (or even on its own) is a 3 wire fan splitter cable. This basically connects 2 fans to one fan power connection, either through the fanmate, resistor cable or directly to the motherboard. This therefore halves the cost of changing the control of 2 fans or gives you the flexibility to run one of more fans at a slower speed than another one (taking into account my ‘be reasonable’ comment earlier). The fans splitters can be obtained in several places including ebay for under a pound (if several are bought at the same time).

You can use these resistor cables on the CPU fan if required, however there’s obviously a greater risk here if you slow things down too much! You also need to take care since using these resistor cables can actually reduce the voltage to the point that some fans don’t have enough power to spin at all, so again be reasonable - the 7v version may be the best one to try out first. Whilst I think you can get great results by using ‘stock’ CPU coolers it’s also worth considering one of the many CPU alternatives available. Many of these are covered in the various forums already, along with the concept of Watercooling.

I never recommend that you make any adjustments to a power supply, including the fan. The best option here is to buy wisely in the first place. There are a number of quality power supplies that are very quiet in normal use. Depending upon your power needs the Hiper PSU’s can deliver great results. If a low noise PSU isn’t acceptable there are some silent, fan-less PSU’s about. The Silverstone one is also available and is likely to cost you around £70. If you need a higher rated PSU there are some available but that will set you back around £100+.

If you’ve a motherboard with a Northbridge fan it’s likely that it will be spinning at 4-5000 RPM and therefore making its presence known. Once again Zalman make a couple of different Northbridge heatsink/coolers that produce great results for less than £5. You will need to take care that they don’t obstruct anything in your build, most commonly a graphics card. They’re also not recommended for systems that are running on built in graphics, so check before buying.

Hopefully if you’ve a HTPC you’ve planned it well and are using one of the many excellent fanless graphics cards about. Although these don’t generate any noise they certainly can produce plenty of heat. You need to make sure that your build has a way of venting this. If you’ve built your system with a powerful fan graphics card it’s very likely that this is the noisiest item in your HTPC now you’ve reduced the noise from the other fans. There are a number of products that either reduce the noise produced by replacing the fan or replace the fan itself with a heatsink type arrangement. The range of cards available means I won’t be going into this further now but one of the replacement fan units that’s well worth looking at is the Zalman VF700 series at around £20.

Hopefully we’ve now produced good results by making some changes to fan speed and noise. It’s now likely that you’ll be picking up the noise from your hard drive(s) and CD/DVD drive more. There are some cheap options here that will help. There are products available that enclose your hard drive in a sound absorbing unit. I’m personally not a fan of these since I think they can end up trapping too much heat. However if you’re interested these devices usually retail around £30+.

A cheaper option is the use of rubber mounting brackets. These come in different styles but working in a similar way to reduce vibration noise levels. They cost around £10-£15 per set and mean that you’ll have to site your hard drive in a larger 5.25 DVD slot, although they can be quite effective. It’s also worth considering Acoustic Noise Management for your hard drive. Some HD’s have the ability to slow the spin speed down. Whilst this does reduce access times it’s worth trying. Not all drives have this facility so it’s worth checking with the manufacturer’s website. It’s also worth trying the freebie Systool which has some Acoustic Management tools built in. Take care if using one of these that it doesn’t install by wiping the hard drive first!

Finally your DVD/CD drive may warrant some attention. As is the case with most PC things speed = noise. With DVD drives seeming to be replaced by newer models with increasing frequency it’s hard to give clues on which model may be the best for a HTPC build, however there are quieter versions around so it’s worth researching. Even with one of the quieter type of drives it’s still going to spin quickly and therefore generate noise. Using something like Nero DriveSpeed allows you to slow the DVD/CD drive down, reducing noise significantly. Some of the OEM versions of Nero contain DriveSpeed and can be obtained for £2-3.

Hopefully that’s given you some pointers and methods for cheaply reducing noise levels to make your HTPC ‘silent’.