Best CPU cooler: 12 top coolers reviewed and rated
8th Nov 2012 | 16:40
We review the best CPU coolers on the market
Best CPU coolers: Introduction
High-end processors are painfully pricey. That makes us grumpy. Even if you could afford to unload £800 on a CPU, we'd therefore prefer it if you didn't. It only encourages Intel to pile on the pounds.
But there is hope, and it comes in the form of improved cooling. Often, the only significant difference between chips priced hundreds of pounds apart is clockspeed. Even with the most basic of cooling, it's often possible to close, or even entirely leapfrog that frequency, and therefore performance gap, but bolt on a better cooling solution and things get really interesting.
A critical factor is the price of cooling solutions. £50 here or there isn't very much when it comes to processor pricing, but it buys you one hell of an air cooler.
While water cooling options tend to be a bit more expensive, even £100 or so for one is mundane money compared to a high-end processor. What's more, CPU coolers have much longer legs than the chips themselves. Six months is sometimes enough for a CPU to transmogrify from shiny to shonky. After a couple of years, you're often struggling to keep up with the latest applications.
But not coolers. Generally, a good cooler today is a good cooler tomorrow. It's as solid an investment as you get with PC kit. The knock-on effect of squeezing more performance from your processor is that it should last a bit longer before an upgrade is critical.
If that isn't enough, there are a few fringe benefits to boot. Running your CPU at any given clockspeed usually means it will be more reliable. Failures are pretty rare, but instability due to heat isn't. Counter intuitively, upgraded cooling is often quieter, too. In fact, sometimes it's silent.
Stick all that together and give it a good stir and you have a winning mix and one of the most cost effective ways to perk up your PC's performance. With all the weird and wonderful cooling designs out there, it's also a lot of fun.
Overclocking ain't what it used to be. Whether that's for good or ill depends on the moment in history you choose for a yardstick. It wasn't all that long ago that it was not only possible, but terrifyingly easy to fry a CPU via an ill-advised overclocking escapade. And remember when overclocking involved shorting circuits by drawing on the chip package with a pencil? Seriously shonky stuff.
These days, it's hard, bordering on impossible, to irreversibly nuke a CPU. You have to do something very, very stupid. In fact, leave the voltages alone and you'll struggle to do lasting damage. So overclocking is a hell of a lot less scary than it used to be. Cue much rejoicing.
But there have also been changes that make it much harder to turn budget chips into giant-killers. Firstly, the CPU market is much more tiered than it used to be. Back in the days of those pencil hacks, the only difference between a high-end monster and a more mundane model was clockspeed.
Today, top chips are often based on different silicon from their bargain basement brethren; more cores, extra features, a different socket and all that jazz. But that's not the only change. Particularly when it comes to Intel processors, overclocking opportunities are very carefully controlled.
Since the introduction of the Sandy Bridge generation of processors, overclocking has been essentially limited to the CPU multiplier. On the one hand, that's great because multiplier overclocks are the cleanest and the quickest. You don't have to worry about the knock-on effects on other sub-systems like memory or the PCI Express bus.
On the other, they're not much use if the multiplier is locked. And locked it largely is on most Intel chips.
Bang for your buck
You have to pay extra for either a K series or an Extreme model to get access to fully unlocked multipliers. It's all very frustrating, but that's what happens when a single vendor dominates the market. Yes, AMD offers fully unlocked chips for much less money, but they're typically lower performing and don't overclock as well.
For that reason, we've based this month's cooling spectacular of our favourite CPU of recent years, the Intel Core i5-2500K. It's not the fastest chip in all areas. Its lack of HyperThreading holds things back a little when it comes to uber-threaded software like video encoding. It's also been recently superseded by the new Ivy Bridge generation and in particular the Core i5-3570K.
But it's still an absolute beast when it comes to games, which are not only our favourite thing to do with PCs, but also just so happen to be the app type that benefits most from performance upgrades. Oh, and the 2500K is also a great overclocker, so it should help sort the high-falutin heat sinks from the clunky coolers.
Despite recent limitations on overclocking, then, there are still opportunities for modders to extract massive performance gains with a good cooler. If we've sold you on the general idea of a cooling upgrade, let's deep dive into the specifics.
Air versus water, that's the classic contest. The most obvious things air-cooling has going for it is cost and complexity. It's generally pretty cheap and almost always simple. In fact given that some air coolers have no moving parts, you couldn't get any simpler. Long term reliability, then, isn't much of an issue.
That's more than you can say for water coolers. At least, that used to be the case with the typically rather Heath Robinson affairs that used to pass for water coolers. The funky blue liquids and clear piping were fun, but they often made for an unreliable system that needed fairly regular fettling - or worse, a terminal leak onto a critical component. Yikes.
Such kits were also far from user friendly in terms of initial set up and installation. Fortunately, little to none of that applies to modern so-called enclosed water cooling solutions. You pretty much pull them out of the box, plug 'em in and crank up the clocks.
Okay, they do come with large radiator assemblies, which make the installation procedure a little less routine, but then fancy air coolers can be a right pain in the parallel port, too. Modern water coolers are also usually meant to be zero maintenance, which means price is the major downside to liquid cooling.
It ain't cheap. The upside, at least in theory, is improved cooling. Funnily enough, though, the principles for both water and air-cooling are essentially the same. In both cases, a block of metal sits atop the CPU and transmits heat to a cooling array via a medium, which, in turn, is cooled by air, either ambiently for a passive cooler or actively with fans.
In the case of so-called air coolers, it's actually heat being conducted through metal. With a water cooler, it's liquid being pumped around the system. So, the choice is really metal versus water cooling.
One thing you generally don't have to worry about, however, is socket compatibility. Most cooling kits are designed to play nicely with existing CPU sockets. AMD's socket has been essentially static when it comes to cooling attachments for years. Meanwhile, most kits will support sockets as old as LGA 775 for Intel kit, which we reckon covers just about everyone, but it's easy enough to check the specs.
That said, you should have a think about compatibility with your current PC case and motherboard, as well as your graphics setup. There are lots of variables to bear in mind here, so it's difficult to come up with simple prescriptions, but you need to generally be aware of the space inside you case and also consider that some of the more extreme coolers can foul the PCI Express slot nearest the CPU socket. If you've got a board with just one such slot, that can rule out certain coolers.
Best CPU coolers reviewed and rated
1. Antec Kuhler H2O 920
Active water cooler
When you first set eyes on the Antec Kuhler H20 920, you might think it's in the same category as Thermaltake's entry-level Water 2.0 Performance water cooler. After all, it's basically a 120mm effort with a radiator between two fans.
Look a little closer, however, and you'll notice that the Kuhler H20 920 sports a much thicker radiator. Just under 5cm thick, actually. It's also packed with a high density of cooling fins, so what we're looking at is an effort to squeeze big water-cooling performance into a more compact, practical package.
2. Corsair Hydro H100
Active water cooler
With a full-length 240mm radiator and what appears to be a very similar spec to the Thermaltake Water 2.0 Extreme for two-thirds the cash, you might think it's easy pickings for the Corsair Hydro H100. In fact, the H100 goes one step further, with a digital fan control button on top of the cooling block that allows you to quickly jump between its Quiet, Performance and Balanced modes.
What's more, the H100 is fully compatible with Corsair Link Digital, which boils downs to a bunch of hardware and software components that give you control over a whole load of performance and cooling parameters.
3. Deepcool Ice Matrix 400
Active air cooler
How much does fancy packaging matter? Ultimately, it can't be that critical, otherwise the Deepcool Ice Matrix 400 would have this thing completely wrapped up. Whether it's the neat little boxes or the lovely, dense white foam padding, there's evidence everywhere that somebody at Deepcool headquarters really cares.
Fortunately the attention to detail spills over into stuff that actually matters. Like the rubberised chassis for the 120mm fan, which is designed to keep vibrations, and therefore noise, to a minimum. It's an innovation that's worthy of a bona fide patent. How do you like them apples, other cooling companies?
4. Gelid GX-7
Active air cooler
When we're talking coolers with aluminium fin stacks and 120mm fans, standing out from the crowd isn't easy, but Gelid reckons its GX-7 can jump up and down and scream enough blue murder to get your attention. Or at least offer something a little different.
For starters, instead of laying out the heat pipes in a row across the cooling block, Gelid uses a partially stacked arrangement. The idea is to have as many pipes as possible running through the hottest part of the block.
5. Nofan CR-95C
Passive air cooler
There's a joker in every pack, and the mantle this month falls to the comically oversized Nofan CR-95C. But is it an ultimately doomed effort à la Heath Ledger, or does this passive cooler have the longevity to slip into the Jack Nicholson category and just keep on trucking?
Strained comic-book villain analogies aside, the Nofan is certainly a little bit special. First there are the gargantuan proportions. This CR-95C model isn't the biggest beast in the Nofan jungle, but at 180mm in diameter it's still an outrageous bit of kit.
6. Scythe Mugen 3 Revision
Active air cooler
Maintaining the low noise levels and temps, while upping the compatibility ante. That's the plan for the third version (revision B, don't you know) of Scythe's Mugen 120mm cooler. That means refined airflow and Scythe's Slipstream noise-optimised 120mm fan.
The result is a cooler with a rated noise that kicks off below 27.4dBA, even if the maximum noise breaches the 30dBA barrier. Other upsides include some of the nicest assembly instructions we've seen, with a proper annotated key to all the parts. Joy!
7. Scythe Katana 4
Active air cooler
Fans 120mm and larger dominate the enthusiast and overclocking market. What hope, then, for the plucky little Scythe Katana 4 and its 92mm fan? Scythe is an experienced outfit and this is the fourth version of the compact Katana, so if it doesn't deliver, it's probably time for the towel-tossing to begin.
As before, the latest Katana is smaller than your average high performance cooler in just about all directions, measuring nearly 100mm square and 143mm in height. The upshot of this is that you're unlikely to find a remotely mainstream ATX motherboard or case that won't jive with the Katana 4. It's not going to tussle for space with your RAM or argue with your graphics card.
8. ThermoLab Trinity
Active air cooler
The ThermoLab Trinity looks like a pretty conventional cooler at fi rst glance. A big fan, a large stack of aluminium cooling fins and some copper heat pipes. Same old.
But this is no knock-off job. Your suspicions should have been aroused by the odd 130mm spec of the cooling fan, where most of the competition goes with 120mm. That should allow the Trinity to either shift more air for a given noise level or shift just as much with a bit less rattle and hum.
It's also a little unusual in that the fan is an integrated part of the cooling stack. It's not a clip-on item. Both of these facts have advantages, but the downside is you can't just whack on another standard 120mm spinner if you fancy pepping up the cooling performance.
9. Tt Water 2.0 Performer
Active water cooler
The Thermaltake Water 2.0 Performer is half the size and half the price, but is it also half the man compared to its Water 2.0 Extreme sibling? In hardware terms, the most obvious loss of masculinity is the half-length radiator. That said, it's still sandwiched between a pair of 120mm fans, instead of having two across one side.
The rest of the cooling hardware, however, is a dead ringer. It's the same cooling block and water pump. In other words, you're not only getting quite a bit more than half the hardware for half the money, the result is also more compact and therefore easier to slip into a wider range of chassis. That, however, is not quite the whole story.
10. Zalman CNPS14X
Active air cooler
This is a serious bit of kit. Let's start with some of the highlights. Six copper heat pipes draw thermals from a polished copper cooling block and feed to two massive aluminium fin stacks. Nestled in between is a 140mm fan that draws air through one stack of fins and squirts it out via the other.
As you'd expect from a big fan, the quoted noise specs are very impressive and top out at just 21dBA. Zalman's idea with the CNPS14X, then, is good thermals combined with excellent noise levels. If you want to tip the balance in the direction of thermals and performance, you have the option of strapping on one or two extra 140mm fans, giving mighty cooling potential,but our benchmarks show the CNPS14X with just the integrated 140mm blower.
11. Enermax ETS-T40
Active air cooler
Here at PC Format, we want the lowest CPU temps available to humanity. We want them here, and we want them now. This is the short version of our CPU cooling manifesto. The slightly longer version, as it applies to air coolers, goes something like this…
Obviously an air cooler needs to do what it says on the tin, namely keep your CPU cool. That includes everything from thumb-twiddling idle mode at stock clocks to balls-out benchmarking with the clocks set to full reheat. And it's not just about achieving low temps in extremis. We want those temps fast.
In particular, we want to see load temperature drop like a stone the moment the CPU goes into idle mode. We also want all that without any fuss, so noise levels low enough that they're pretty much inaudible once installed in an enclosed PC case.
12. Thermaltake Water 2.0 Extreme
Active water cooler
Liquids and finely honed electronics. You'd be mental to mix 'em. Your correspondent recently proved this beyond all doubt by entirely submerging his iPhone in a puddle. But have no fear. The latest fully closed loop water coolers are kosher. There's none of the slightly scary shonkiness of yesteryear's home-build kits. And there's a lot less faff when it comes to initial setup too.
Less faff, that is, but not quite no faff. Thermaltake's Water 2.0 Extreme, for instance, is a bit of a chore when it comes to the sorting socket clamp and board bracket assemblies. But once you've nailed that job, it's plain sailing in terms of installation, and thereafter it's a doddle to whip the cooling block off and swap out the CPU or replace the whole shebang with another cooler, if need be.
How we tested
Just how cool can our coolers really cool?
Our test platform involves our favourite CPU of recent years it just so happens to be a great little overclocker too, the Intel Core i5-2500K. We've paired it with an Asus Z77 motherboard because Intel's latest performance chipset seems to squeeze more out of its CPUs and Asus boards are the most consistent performers.
As for the settings and benchmarks, where configurable, we set fans to balanced rather than ultra quiet or high performance mode and then tested temps and performance at both stock clock speeds and the maximum overclock possible with each cooler.
We chucked in some Cinebench rendering and World in Conflict gaming tests to get a feel for performance comparisons and also to quantify the impact of any clock throttling.
And the winners are...
Thermaltake Water 2.0 Extreme
Twelve coolers, a bucket load of thermal paste and plenty of overclocking action. But what have we learned?
The first thing you should appreciate is that water-cooling isn't the magic solution to giving you instant access to epic overclocks. At least, no more epic than you'll achieve with a decent air cooler.
Admittedly, the gap between air and water when it comes to overclocking will grow if you really put your back into the fine-tuning. But in our view, the advantage of water when it comes to achieving really high clocks isn't worth the price premium.
Part of the explanation for that is conventional liquid-cooling is ultimately subject to the same limiting factor as air cooling, namely ambient temperatures. You need some kind of refrigeration or Peltier system to overcome that.
Liquid cooling still has a place though. The reason to go with water is to achieve lower operating temps for less noise. What's more, a decent closed loop water cooler tends to have longer legs than an active air cooler since they're that little bit less sensitive to dust than an air cooler. In fact, if you locate the radiator outside of the chassis, you can give it a bit of a buff without cracking open the case.
As it happens, reduced dust build up is also a key advantage of passive air cooling, along with zero noise emissions. However, as our benchmarks show this month, even a comically oversized passive cooler can't compete with very modest active air coolers, much less water coolers, when it comes to performance.
With that in mind, it's the hilarious but ultimately almost pointless NoFan CR-95C that brings up the rear this month. Put simply, relying on convection for cooling makes for some horrible temperatures. Just as important, several of the active coolers here produce extremely low noise levels. There's just no need for a desktop computer to have a completely silent CPU cooler.
Next to fall, if largely on a technicality, is the Antec Kuhler H20 920. Thanks to a fault with the fan modulator that caused its two 120mm windmills to spin at full speed, it's hard to know what it's really capable of.
From here we get into a much closer contest. The Scythe Katana 4 was interesting in that it underlined the downsides of going for something smaller in the air-cooling category than the default 120mm option.
However, it's the Enermax ETS-T40 and Thermaltake Water 2.0 Extreme that really set themselves apart. The Enermax performs well beyond its pay-grade and makes the oversized Zalman CNPS14X look a little silly. It also proves you can have great cooling without the compromises that come with really massive coolers.
Meanwhile, Thermaltake's Water 2.0 Extreme, which takes the water-cooling spoils in this test, is pricey, but then liquid-cooling is a bit of a luxury, so why not have something a bit special? It's built to last, is a great performer and it's even better with that USB interface and control software. In short, it's a proper bit of kit.