How hot does your CPU really get? If you're talking about some low-end AMD Fusion beastie or a limping Intel Atom chip, then the short answer is: not very.
If you're on about a fully fledged multi-core number, though, you may just be generating enough heat to cook a plum duff. Tasty, yes, but bad for your rig.
With those lower-end CPUs, you can even get away with passively cooling them. That means no fans and no spinning, whirring noises to disturb you. You can't do that with higher-spec chips, since they work harder and thus get hotter, meaning you will almost always need an active cooler to keep your CPU running effectively.
Of course, you could set up a heatsink the size of the mighty Greg Davies, but finding a chassis to house such a beast will be tricky. So if an active cooler is the practical solution to heating woes, what of liquid cooling?
Traditionally, this is a realm that's been left to either professionals or the suicidal tech journalist, but the rise of the closed-loop, all-in-one liquid-based coolers means everyone else can have some of that watery goodness too.
It used to be expensive, but the likes of Antec's latest Kühler have helped to drive down the price, making it accessible to the masses who don't have masses to spend.
That doesn't mean the heatsink and fan combo is out of touch, though. Indeed, it can keep both the CPU and motherboard chilled, instead of just the former. Given the £15 asking price of the Xigmatek Loki, you can't really argue with the tech.
Another issue to consider is scale. There's a finite amount of space in any given chassis, so you may be in trouble if your heatsink is too monolithic. Fear not, though, as we've dug out the best CPU coolers to keep all kinds of cases frosty and leave your wallet full enough for a cool beverage when you're done.
Alpenfohn Matterhorn - £45
Web: www.alpenfoehn.de
Imposing, cold and tall. You could think Alpenföhn's Matterhorn was so named because it shares these properties with the Alpine mountain. We prefer to think it's because it kills 12 climbers each year, but that's just us.
The supplied fan does a good job, generating very little noise even for a 120mm unit, and it's possible to mount a secondary one too. Despite the six heat pipes, we're not blown away by the unloaded performance, though.
While it's a healthy 12°C cooler than the stock unit, the solid copper base can't keep up with either the Xigmatek Gaia or the Prolimatech Armageddon, which is possibly due to both of these using a direct-touch design.
Under load the Matterhorn ups its game, drawing level with the Gaia and showing its 6mm heat pipes can shift as much warmth as three 8mm ones. Both are priced similarly too, so they're tough to choose between.
Temperatures
Idle: 65°C
Load: 69°C
Verdict: 84%
Antec Kühler H20 620 - £49
Web: www.antec.com
We know liquid cooling's cool, but its development seems glacial in speed. The new Antec Kühler H20 620 could change the status quo, though.
It's a drop-in liquid cooling solution that works, and works quietly. Priced at the same level as some high-end air coolers, such as the Genesis, yet costing less than the zany V10, the Kühler offers a number of clear advantages over more complex and costly liquid systems.
We liked its engineering; the unit feels well constructed, plus its installation process is easy to follow and well thought out.
Basic performance is adequate and under load the Kühler does an efficient job, even if it's outperformed by some of the air coolers here. The kicker is that some of these are also cheaper, such as Titan's Hati and the Xigmatek Aegir.
That said, if you want the quietness of water cooling, then these considerations don't detract from the overall good performance on offer.
Temperatures
Idle: 63°C
Load: 66°C
Verdict: 89%
Cooler Master V10 - £85
Web: www.coolermaster.com
Now that is one big cooler. It delivers a phenomenal spec list in one mammothly proportioned package. Measuring 24cm long and 16cm high, it's packing two 120mm fans, three heatsink arrays, 10 heat pipes, and there's even a hybrid TEC heat pump buried inside there as well.
Can all that be put to good use? Not really. We like the attempt to create a dedicated, more all-round cooling device, but in its attempt to bolt as much on as possible, we think Cooler Master has lost sight of simple, efficient cooling.
Installation is tricky and causes issues with memory. With a unit of this size and price, we'd also have expected some type of manual fan control on top.
Considering the twin fans, it's not overtly noisy – you won't miss it running, but it does produce a good, clean fan noise. For the levels of cooling the V10 provides, however, even that noise isn't really justified.
Temperatures
Idle: 63°C
Load: 68°C
Verdict: 69%
Prolimatech Genesis - £55
Web: www.prolimatech.com
Bigger appears to be better if the Genesis air cooler is anything to go by. Taking on the likes of the V10 and the Gaia, this twin-heatsink air cooler uses six fat 8mm heat pipes that elegantly coil their way off to the twin sets of heatsinks. Once hooked up, the Genesis blew us away, and not because of the fans.
Its unloaded performance matched that of the equally impressive Armageddon, and altogether running a notable 17°C cooler than the stock unit. The performance is the one thing to take away; it's excellent.
Couple that with a reasonable price tag and, if you don't mind supplying your own fan, you're onto a winning combination here.
That said, the Genesis is a large cooler and that's going to turn many people off. Adding two extra fans to the price is also going to push the total cost way above something like the Aegir, which does a perfectly adequate job.
Temperatures
Idle: 58°C
Load: 61°C
Verdict: 91%
Prolimatech Samuel 17 - £40
Web: www.prolimatech.com
We can't say Prolimatech doesn't know what it is doing, because the Genesis is one of the best air coolers we've seen. However, it was aimed at the high-end market.
The Samuel 17 is a low-profile cooler designed for the slimmer system, most commonly a home theatre PC. Its performance is unquestionably good for this style of cooler, but it's still a way off an entry-level third-party cooler with a fan.
In comparison, Alpenföhn's Panorama is half the price and comes with its own fan pre-installed. For six heat pipes, we would have perhaps expected even better overall cooling, although the results we achieved were good.
We're also not big fans of the rear-mounting system, but it's understandable, since otherwise it'd be impossible to fit with a 120mm fan.
The main issue, though, is its price, which is high for something that offers below-average cooling and comes without a fan.
Temperatures
Idle: 68°C
Load: 73°C
Verdict: 75%
Titan Hati - £38
Web: www.titan-cd.com
In many ways, the Titan Hati demonstrates the importance of straightforward cooler design. It's simply been made to get the heat out of the CPU spreader and get rid of it.
Easily competing with the Xigmatek Aegir for the best mid-range cooler award, the Hati puts in the sort of cooling performance seen in units costing far more. Its direct touch design and no-nonsense, 8mm heat pipes mean it's able to carry off more heat than other competitors.
Titan also uses an interesting fan design that seems to work well, shifting a good volume of air without producing too much noise, considering we ran the fans at full speed for testing.
In contrast, the mounting system feels like a Heath Robinson contraption, but does a solid job once it's been carefully constructed. Yes, the base could do with slightly better engineering, but that doesn't detract from the Hati's confident performance.
Temperatures
Idle: 61°C
Load: 65°C
Verdict: 92%
Xigmatek Aegir - £42
Web: www.xigmatek.com
A mid-priced cooler, the Xigmatek Aegir has the specification of a somewhat higher-end model. Oddly, at this price it's competing with the Xigmatek's own Gaia, but then the company seems to have more models than it knows what to do with.
Unusually, the Xigmatek Aegir has a layered heat pipe design that uses different-size tubes. Two central 8mm pipes are trapped in place by two 6mm cylinders either side and two more 6mm tubes on top. The whole unit is finished off by a high-volume 120mm fan.
We like almost everything about the Xigmatek Aegir, from its high-volume fan that can shift buckets of air with little noise to the unusual layered heat pipe design that does a grand job of sucking all the heat away from the processor.
The icing on the cake is the price. Our one annoyance is the mounting system, which makes installation harder than it should be.
Temperatures
Idle: 61°C
Load: 65°C
Verdict: 89%
Xigmatek Loki - £15
Web: www.xigmatek.com
Described as a budget cooler, the Xigmatek Loki SD963 looks like a performance unit, but it certainly doesn't have the price to match. Only the smaller 92mm fan and the thinner 6mm heat pipes give away that it's not on a par with the other coolers here in terms of cost.
What's not to like about this little cooler that could, though? Sure, you could spend £5 or so on a stock cooler, but for just a tenner more the Loki provides performance cooling without much added noise.
Since it's also capable of supporting a twin-fan cross-flow installation there's even more room for cooling or noise reduction, and that universal mounting system gives it the advantage of flexibility as well.
Obviously, a 120mm fan would be preferable, and universal mounting systems are always tricky to install. But that's just being unnecessarily picky, since we're struggling to find anything else that's negative to say about it.
Temperatures
Idle: 68°C
Load: 63°C
Verdict: 90%
Technical analysis
We tested on an overclocked Core 2 Duo E6420. Each cooler was run for 20 minutes to get the idle temperatures. Then we fired up MaxCPU to crank usage up to 100 per cent and left the system for 10 minutes, to give us our full load.
No cooler really struggled, although size can clearly be an advantage, with the Genesis leading the field by a decent margin. Some of the smaller boys were taxed under full load, though. Not to the extent that they'd render a system unstable, but they're not ideal if you plan on overclocking.
