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%