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BOOT CAMP 259 (21/01/03)
KEEPING YOUR COOL
Back in the mid 1980s, when Amstrad started making IBM
‘clone’ PCs, one of its first models had the mains power supply module built
into the monitor. The electronics in the compact desktop box, which didn’t
generate much heat, was cooled by natural airflow but a fanless PC was unheard
of and there was immediate concern that it would overheat. Many potential buyers
were put off by the adverse publicity, Amstrad relented and fitted a fan to the
system box, even though it wasn’t needed and didn’t actually do anything, but it
solved the problem and everyone was happy.
Today no PC is complete without at least two, and sometimes
three or four fans whirring away in the background but these days they’re much
more than a customer relation’s exercise. PC power supply units (PSUs) have
always had fans, both to dissipate the heat they generate, and to draw cooling
air into the PC’s to vent the heat produced by the chips on the motherboard and
disc drives. On-chip CPU cooling fans first appeared on the 486 family of
processors and they’ve been with us ever since.
Those early pre-Pentium chips used to get quite warm but you
could easily fry an egg on the latest generation of super fast processors and
some types will destroy themselves within a few seconds if they are not
adequately cooled. However, it’s not just the CPUs that need cooling, almost
everything inside the modern PC gets hot in the relentless quest for speed and
performance every component, from hard disc drives to memory modules and video
adaptors are being pushed to the limit and PC cooling has become a hot
topic…
Inevitably cooling fans fail so you should recognise the
symptoms, and know what to do when it happens. Any change in the sound your PC
makes should put you on the alert. Cooling fans rarely just stop, but if for
some reason you don’t hear the familiar whirring sounds switch off immediately
and have it seen to, as there’s a very real chance of damaging the CPU.
If the fan sound becomes intermittent, or it makes a buzzing
noise this may be coming from a wire or cable brushing against the blades of the
on-chip cooling fan. Again take this as a warning and switch off immediately. If
you are happy to remove the case lid it’s worth having a look (remember to
switch off and disconnect the PC from the mains first). Anything fouling the fan
should be very gently moved out of the way; if it looks as though it’s going to
spring back use a plastic tie-strip to keep it out of the way.
Fans often warn of imminent failure and emit a high-pitched
whining noise, indicating a dry or worn bearing. On-chip cooling fans can be
quite difficult to replace. They’re usually held in place by a pair of strong
spring clips. These may be tricky to get at or obscured by the power supply
module and cables. If you attempt a DIY
replacement don’t try to work around the obstructions, remove the PSU and at all
costs avoid prying the retaining clips free with a screwdriver. It’s bound to
slip and the tip of the screwdriver can fly off and do serious damage to
components on the motherboard. If you have the slightest doubts about your
abilities consult an expert.
If your CPU fan fails consider replacing it with a more
effective design; in any event avoid cheap CPU fans as they have a poor record
for reliability. With something as important as CPU cooling it’s always better
to have something in reserve so opt for a fan that’s overrated for your
processor, or one of the new high-efficiency ‘Flower Cooler’ designs. These have
large heat sinks made up of hundreds of separate fins or ‘petals’; they also
tend to run a little quieter. Silent or muffled fans are also available if you
are troubled by noise but the ultimate in PC temperature control has to be
water-cooling or CPU refrigeration. Specialist cooling systems are available for
server PCs and they’re popular with ‘overclockers’.
The fans in power supply modules generally last the life of
the PC but they can become less efficient as they get clogged with dust. Loose
dust and debris can be sucked out from ventilation slots and the fan grille on
the back of your PC with the accessory hose on your vacuum cleaner. PSU fans can
be replaced but it’s a job for an engineer, moreover there are many different
types and fittings so it is often quicker and easier to swap the whole module.
Replacement PSUs are available from most PC dealers and companies like Maplin
(www.maplin.co.uk) and prices start at
around £40.
PC cooling systems become less effective over time and this
can have an effect on performance. Some CPU chips, notably Intel Pentium 4
types, have built in temperature control and will automatically reduce their
speed when they get hot. Many AMD processors have little or no thermal
protection and they can be permanently damaged if they are allowed to
overheat.
The actual temperature at which damage or a slow down in
performance occurs varies from make to make. Some CPUs are designed to run at a
fairly modest 60 degrees Celsius whilst other perform quite happily up to 90
degrees but rather than waiting for something to go wrong you may be able to
take advantage of the fact that many recent motherboards have built in
temperature sensors. A simple freeware utility called Motherboard Monitor,
available from http://mbm.livewiredev.com/, displays CPU
temperature and fan speed and can be set to automatically sound an alarm and
shut the PC down if it exceeds a pre-set limit. Check first that your
motherboard is suitable by clicking on the Motherboard List link under
‘Information’ and you’ll also find links to CPU manufacturer’s web sites for
details of operating temperatures.
Next week – Portable Data
JARGON FILTER
CPU
Central
Processor Unit - the main microprocessor chip in a PC
OVERCLOCKING
Making a PC run faster by increasing the speed of the CPU
beyond its rated design
WATER COOLING
Very similar to the cooling system in a car with heat drawn
from the CPU chip inside liquid filled pipes to a miniature radiator and fan.
TIP OF THE WEEK
As you install more software on your PC changes are made to
the Registry, which can slow it down and make it less stable. RegSeeker is a
freeware Registry cleaning utility that weeds out unused or unwanted entries. It
does much more besides, including displaying Startup information and it allows
you to look inside ‘hidden’ history files like Index.dat, which secretly records
your Internet activities. The download and more information can be found at: www.hoverdesk.net/freeware.htm
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