Corsair H70 Review Page: 1

Corsair H70 Review


Ahhh bigger. We like bigger. No matter what it is, when it comes to PC hardware, bigger is nearly universally better. Bigger hard-drives give more space. Bigger RAM gives improved application performance. Bigger heatsinks gives better cooling.

The same is true of radiators. A bigger radiator in your house produces more heat. A bigger radiator in your water-cooling loop gives lower temperatures.

Of course there are some limitations to size. You'd never fit a Noctua NHD14 into a HTPC case for example.

As you can probably tell from the cooling theme of the introduction, todays review is of something that is bigger, and therefore hopefully improved, version of a CPU Cooler we've previously tested here at OC3D.

When we tested the Corsair H50 we found it had a great mounting system and reasonable performance for a self-contained CPU water-cooler. However it just didn't have either the rad-size or pricing to be a sensible alternative to a high-end heat-pipe tower style air cooler.

Corsair have have been busy beavering away in their labs and have produced the H70. So before we take a look at this big brother to the H50, let's grab the features off of the Corsair website. 





Cold Plate MaterialCopper

Fan Specs

2 x 120mm, selectable 2000RPM or 1600RPM

Radiator Material


Low-permeability for near-zero evaporation


The main improvements are an improved CPU block/pump and a much larger radiator. As well as the inclusion of two fans in a push-pull setup. Certainly on paper it has everything that the H50 needed. So let's take a look.

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Corsair H70 Review

What's in the Box?

The H50 box was nicely designed, but suffered from incredibly thin plastic holding it all together. It was perfect if you never wanted to put the cooler back in the box, but an absolute nightmare if you did. Straight away the H70 is an improvement with egg-box style cardboard keeping the whole arrangement nicely in place and making it as easy to store as you could hope.

The front certainly stands out leaving nobody in any doubt of what is in the box. Although we can't wait to hear the "I expected it to have some RAM in there" thanks to the cheeky use of a stick of Dominator in the picture.

Corsair H70 Review     Corsair H70 Review  

The universal mounting system is identical to that which we saw on the H50. It was so simple to use there that we're pleased to see Corsair haven't tinkered for the sake of it. So often we find things work perfectly well and then get needlessly changed for the sake of change. Anyone who's tried a one-sided webcam conversation on the new Windows Live knows what we mean.

As well as two of Corsairs fans we also have some adaptors in the box. There are two with in-line resistors for fan speed reduction, and a y-splitter so you can run both fans off one header. Very welcome additions to the package.

Corsair H70 Review     Corsair H70 Review  

Here it is in all its glory. The difference between this and the H50 is instantly noticable. The radiator is 50mm thick, twice the thickness of the H50, and once you get both the fans on there it certainly will be a fair lump to install.

Flipping the size thing around, the heatsink/pump combination is greatly reduced in height.

Corsair H70 Review     Corsair H70 Review  

The largest annoyance when trying to fit the H50 was how inflexible it all was. Installing the heatsink meant having the radiator flapping about and hitting you in the arm/side of the head. If you installed the radiator first then the pump would be waving around in the air. Although the tubing isn't enormously more flexible, there is at least a little more suppleness to the H70s arrangement.

The best improvement though is the addition of rotating fittings which really help not only installation but also radiator placement. With some ITX or mATX cases you could mount the radiator at the front now, which makes far more sense considering Corsair want you to use it as an intake and not an exhaust.

Corsair H70 Review     Corsair H70 Review

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Corsair H70 Review

Testing Setup

Whilst we could test on a variety of sockets and chips thanks to the excellent mounting solution, with any CPU cooler it's best to see what the worst case scenario would be, and so that means handing it over to our tame racing driver. Oh hang on. That means placing it upon Intels toaster, the Core i7. Today we're using the Core i7 930 which is an improvement upon the 920, but still on the 45nm process and so can still pump out all the heat we could ask anything to handle.

We are testing the i7 930 at three different speeds. Firstly we have everything at stock. Secondly a 700 MHz overclock using 1.35v. And finally the full-fat 1.1 GHz overclock to 4 GHz, also using 1.35v.

Fans were run both at 100% 12v setting, and using the low-speed adaptor. The H70 is by no means quiet at 12v, and we always like to test using settings the average user would have.


Our first graph is giving the H70 an absolute thrashing by using Prime95 to stress the CPU as much as is possible. However we are fully aware that Prime is an extreme test and so we're also showing results using 3D Mark Vantage, which should replicate some hard-core gaming.

The first thing to note is how well the H70 handles the i7 at stock speeds. Under 60°C whilst running Prime is very impressive indeed. Naturally the increase in voltage and workload our overclocks bring quickly increase the heat and even with two fans and that big radiator the H70 struggles with 4 GHz. Over 80°C is not something we like to see at all.

Once away from the insanity of Prime though, the H70 can bring the 4 GHz temperatures to around the levels of a Prime 3.6 GHz overclock. These are very handy temperatures, especially considering the exacting nature of the CPU tests within 3D Mark Vantage.


Putting the fans back up to 100% and running at stock, the H70 just beats out our beloved Noctua NH-D14 and is 4°C ahead of its little brother the H50.

Sticking with the 3.6 GHz setting we used above for the overclock the H70 produces a surprise. Even with the two fans attached and the larger radiator it still gives roughly the same result as we saw with the H50, and moving to a single fan it's obvious that the extra girth of the radiator can be a detriment. There definitely is a limit to the amount of cooling available because whilst the NH-D14 sees a 9°C increase when overclocking, the H70 is a full 17°C hotter than at stock.

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Corsair H70 Review


So does bigger mean better?

At the risk of giving a vague answer, sort of. Bear with me.

The H70 has many improvements over its smaller brother the H50. The tubing isn't as rigid and the addition of flexible mounts on the block itself certainly makes the installation of the actual cooler much easier than it was before.

The packaging is greatly improved too. Whilst we appreciate that not everyone is likely to want to re-box the cooler at any point, given the versatility it provides thanks to its brilliant mounting system, you can certainly move it from system to system and so it's not beyond possibility that you'd like to put it somewhere between upgrades. It's also much more likely to protect the cooler prior to arrival than the H50s paper-thin plastic effort.

Cooling capacity and physical size though present a more difficult area to nail down.

Starting with our overclocked i7 results, assuming you're not spending your days using Prime then the H70 can certainly handle even a 4 GHz overclock. When you take into consideration the LGA1366 i7 generates far more heat than a LGA1156 chip, and WAY more than any AMD you care to mention, the results are even more impressive. At stock speeds it's up there with the very best coolers around, keeping everything nice and cool even using the low-speed, and much quieter, fan settings.

This however is exactly the thing that makes it an odd choice. One of the primary benefits of the H50 was the amount of space it left around your CPU socket to help give good airflow across the rest of your components such as the northbridge, MOSFETs and RAM. The H70 though, despite it's much smaller heatsink and pump, is enormous in comparison. The radiator is twice as wide and with two fans you're almost taking up the same room as a tower cooler.

If you run an AMD system and so have much less heat to disperse therefore, the H70 isn't really the one to go for because the H50 will cool equally as well and yet take up less room. Not to mention it is around £30 cheaper.

If you run an Intel i7 system, then up to a point the H70 can handle a heavy usage overclock with aplomb. But again the price bites it somewhat as it's still substantially more expensive than an average air-cooler, and a good twenty notes more than the class-leading Noctua NH-D14, without providing the same level of cooling.

So if you have you heart set on a plug and play water-cooled CPU, or have fierce brand loyalty to Corsair, then the H70 can be recommended. The build quality is great. Installation is a breeze and it will fit anything you want to attach it to. If you just want something that cools your CPU then there are better, cheaper, air alternatives around.



Thanks to Corsair for proving the H70 for todays review. Discuss in our forums.