Anybody who has been near their share of computer
systems will appreciate that not all systems make the same amount
of noise. There are a number of reasons for why this is so. Firstly,
a computer makes noise for different reasons. Generally, anything
mechanical is going to make noise. So, in a PC, that's the hard
drive(s), optical drive(s) and fans. In general, however, fans make
the most noise, and so a quiet cooling solution is the easiest way
to make the entire PC much quieter.
Some PCs don't need quiet cooling. A server, in a room full of
other servers, which have fast, noisy hard drives and a hefty air
conditioning unit, wants the best possible cooling without costing
a bomb, and there's no need for it to be quiet. At the other end
of the scale, a computer in a recording studio might want to be
extraordinarily quiet. To achieve this, the PC case might even be
moved into a separate room.
Of course, most people reading this just want their home or office
PC to make less noise. Readers interested in building a quiet PC
for their living room might also want to pay attention to this Tek
Spek.
So, we've already established that the most effective means of
making a PC quieter is to concentrate on the cooling. The best time
to consider this is before you even buy components. Think about
the case; think about the purpose; think about the demands; and
then find a cooling solution that works effectively, but quietly.
Before you get alarmed and think we're about to suggest you dive
into water-cooling or something more sinister, be assured that this
is not the case. Such cooling solutions are in most (but not all)
situations, excessive. Certainly for fairly general usage, careful
choice of 'air cooling' solutions will be sufficient. Here are a
number of aspects to consider:
Heatsink
The heat sink is usually the noisiest part of the PC. More
specifically, the fan on the heat sink is. The CPU need good cooling
to operate error free. An aluminium or copper block draws heat away
from the CPU, into fins, which then dissipate that heat into the
air, with the help of a fan. The problem is, these fans can be noisy.
If you don't care about noise, then this really isn't a big deal,
as long as the cooler keeps your CPU cool enough. However, when
noise is an issue, it's important to be a bit more picky. The first
thing to look for in a CPU cooler is how big the fan is. A larger
fan will generally be able to move the same amount of air as a smaller
fan, but without spinning as fast. This results in less noise.
A 5000rpm is probably going to be quite noisy. A 2000-3000rpm fan
will be better. Even lower is fantastic. Of course, all the time,
check the specs of the cooler to make sure it can cope with your
CPU.
The fan itself might not need to spin as fast if the rest of the
heat sink is designed better. Different materials and designs dissipate
heat more effectively. A heat sink with thinner fins, but more of
them, has a bigger surface area with which to shift heat. As a result
it can have a quieter fan.
More elaborate coolers use heat pipes. These draw heat away from
the source very quickly, to another location where the heat can
then be dissipated into the air. While more expensive, these solutions
can often be quieter (but not always.)
Always check for a decibel (dB) rating on a cooling component.
Ideally it should state how far away the instrumentation was when
the reading was taken (your PC will sound silent if you try to listen
to it from 100 metres away.) 40dB is certainly noticeable, 30dB
less so, particularly if there are other noise sources in the room.
Even less is great, but take such ratings with a pinch of salt.
PSU
Power supplies, just like CPUs, need good cooling. It's
imperative that they keep cool, or else they won't provide stable
power... or even blow up. That doesn't mean they need to sound like
a wind tunnel, however.
A well designed PSU will maybe use one large fan, or two well placed
fans, to cool nice big internal heat sinks. Three fans might look
good on paper, but this might not necessarily mean they're quiet;
they might be compensating for bad internal design.
Be careful with PSU choice. Cheap PSUs are, in our experience,
not reliable if you expect the full stated load of them. A cheap
and silent PSU seems even more troubling. Make sure you buy a PSU
that is of a quality to meet your power demands while not making
too much racket.
Graphics card
Believe it or not, graphics cards can be noisy. This is
especially true for higher-end models. Luckily, they're often temperature
controlled (more on that shortly.) However, if they're always going
to be hot (say, you play games a lot) then it doesn't really matter,
does it? Graphics cards with special cooling solutions can cost
a little more, but they need not cost the earth.
You can buy third party cooling solutions for your graphics card
if you want to keep the one you have. They can be easy or hard to
install – it depends on what you buy. Read up on things like
compatibility and installation instructions before making a purchase.
Case fans
In general, any fans supplied with a case are going to
be cheap. We're talking very cheap here, and so chances are they're
going to be noisy. Some cases do have decent fans, however, so don't
write them off until you've actually heard them.
If it turns out that they're a bit noisy for your liking, replace
them. It's a good idea to buy a case that has mounts for large (120mm)
fans, but even 80mm fans can be quiet, if you buy the right ones.
Fan control
Fans don't need to be running at full speed all of the
time. When the system isn't fully loaded, it's not putting out as
much heat. Manufacturer's know this, and so some devices, such as
PSUs, graphics cards, motherboards, etc, have temperature controlled
fans, or fan power connectors.
You can add temperature controlled fan support by buying a fan
controller designs for such a purpose. Some are more advanced than
others, with digital settings and customisable thresholds. However,
it that seems a bit too costly, consider the 'fanbus'. These essentially
give you manual control over a fan's speed. A fanbus usually supports
three or more fans, depending on what you buy. They might be integrated
into another device, like an 'all-in-one' front panel, or they might
just be a front panel insert with a few knobs on the front. These
are great, providing you know when fans need to be turned up a little.
Fan controllers can work in more than one way. Some change the
voltage to the fan. This is similar to what you can do yourself
by rearranging the fan's power connector (something this article
doesn't go into). The problem with this is that some fans don't
like lower voltages and won't spin very well.
Another method is called pulse width modulation (PWM). This is
generally more common these days. PWM provides full voltage to the
fan, but only for a certain percentage of a cycle. A 50% duty cycle
means that 50% of the time the fan gets 12 volts, but the other
50% of the time it gets 0 volts. The speed of the fan is controlled
by adjusting the duty cycle. Depending on the PWM implementation,
this can work well, but fans with lights in them might flicker.
Fan controllers are often rated to a certain power. Any wattage
above that could burn them out. Usually, fans don't draw enough
current for this to be a problem, however.
The Market
Companies are always looking to trump one another. Don't expect
the best looking cooler to do the best cooling job. Sometimes the
quality is only skin-deep. Check for reviews to see how well a product
performs and how noisy it is.
There are some great innovations out there, like use of heat pipes,
or clever orientations of coolers, or fan designs. Thermal loads
don't seem to be getting much lighter, and so companies need to
keep finding new, better cooling methods. This keeps the market
quite fresh and competitive, which is good for the buyer.
If performance and silence are key, make sure you're buying a product
that gets good reviews from reputable sites online and seek the
advice of forums too. With so much choice, a little research will
go a long way.
The Players
There are innumerable player in the cooling market. Some make cases,
some make heat sinks, some make fans and so on. A few big names
are worth mentioning, however.
Enermax, Silverstone, Lian Li, Hoojum, Chieftec, all make cases
which serve different purposes. For example, many of Silverstone's
products are geared towards home theater usage, while Hoojum make
small form factor cases.
Akasa are quite well known for their cooling products, as are Zalman
(who specialise in quiet cooling) and Swiftech. There's often a
lot of crossover between case manufacturers and heat sink manufacturers.
In general, a company's heat sinks are as good a quality as their
cases. There are some companies who don't build cases, however,
like Gigabyte (better known for motherboards and graphics cards)
who still make decent heat sinks.
As for fans, Akasa are once again a player. The quietest of the
quiet tend to be made by Panasonic under the 'Panaflow' name. Other
names include YS-Tech, Delta (more commonly associated with screamingly
loud fans, but they also make quiet ones), Thermaltake and many
more.
