Corsair H70 Review

ccokeman - 2010-05-29 18:02:15 in CPU Cooling
Category: CPU Cooling
Reviewed by: ccokeman   
Reviewed on: August 29, 2010
Price: $109


A cooling solution that brings temperatures down on your high-dollar CPU is a good thing! We all know that the stock CPU cooling solutions as supplied by the manufacturers are what could be called adequate (at best). Most people have no inkling of the high temperatures delivered by the stock cooling solution in that cramped OEM-style case (with just a single exhaust fan to remove the harmful heat from your case). For the vast majority of computer owners, the CPU toils away under all that added heat until one day the inevitable happens. The computer just won't work. That of course will not do for anyone and especially will not do for the enthusiast who is looking for longer life and cooler operating temperatures. You can always go big with some of the massive air cooling solutions but, moderate the size, scope and costs a bit and you can get a decent mid-range cooling solution. However, anything more ambitious than air cooling is usually reserved for the adventurous. Water or liquid cooling has always been for the more adventurous of us since liquids and electricity rarely make good bedfellows. You could build yourself a really nice water loop that contains all the components used in this Corsair H70 but then you'd have to worry about matching components, tubing sizes, which water block to get and of course the radiator and pump which must match everything you've selected. When you get down to it, the process is pretty complicated. So, why not move on to an all-in-one solution like the H70? It's pre-filled and sealed for a long useful life and scales well with higher CFM fans as the load increases. Lets dig into the H70 and see how it fares in its quest to become one of the best cooling solutions available to the consumer.


Closer Look:

The panel of the packaging for the Corsair Hydro series H70 shows a closeup view of the pump assembly mounted and in operation. A picture of the complete cooling system is off to the left to give you an idea what you are going to be installing. Information on the front panel includes a list of socket compatibility, the Corsair logo and H70 product identification. The back panel contains a graph that shows the relative performance of the H70 versus a stock Intel cooling solution. To the left side you have a list of contents and under the graph is a short synopsis of the benefits of using the H70. The left side panel lists the specifications in multiple languages.












Opening the box, you find the manuals and a warning label imploring you not to return the H70 back to the point of purchase. Under the foam block that holds the H70 in place is a formed cardboard tray that holds the cooler and all of the accessories. Once pulled out of the packaging, you get a quick view of what's included.



The accessory bundle that comes with the Corsair H70 includes everything needed to put it into immediate use. Socket compatibility includes all of the current sockets from both Intel (775,1156 & 1366) and AMD (AM2 & AM3). What you get is a series of manuals that detail how the H70 is to be installed, the mounting hardware for both CPU manufacturers, a pair of low speed fan connectors, a "Y" connector to power both fans from a single source and a universal parts kit. Included in this kit are the fan mounting screws and pump retention hardware.



Lets take a walk around the H70 and see what makes it a better cooling solution than the H50.

Closer Look:

Stripped down to its bare bones, the Corsair H70 at first glance looks like many of the pre-assembled and pre-filled liquid cooling solutions on the market today. You have the pump assembly, non permeable liquid lines and a radiator. Simple right? When you put it in those terms yes. But when you dig deeper, you get a feeling that something is different. The radiator is larger and the pump/coldplate assembly has a much lower profile than even the CoolIT ECO. The H70 looks like it is based off of the Asetek 570LC liquid cooling system.


















The radiator is a step up from the one used on the H50. Total dimensions are close on both height and width but where it is significantly larger is in the thickness. At 50mm, it is twice as thick as the one used on the H50. With this increase in size, you get an increase in the total surface area. This increased surface area (and now larger internal volume of coolant) leads to a higher heat dissipation capacity that can result in lower temperatures under load. Also, if you are into water cooling you know that mixing metals usually leads to bad things in the long-term due to galvanic corrosion. The radiator here is made of aluminum which is lighter and more efficient at transferring heat than a copper/brass radiator. The coldplate is made of copper so you end up with two dissimilar metals in the loop. However, with a warranty of 24 months you have the expectation that you will not have problems for at least that long or longer. That's long enough for CPU socket changes to render your system obsolete and move on up to the next greatest thing.



The pump/coldplate/reservoir is a low profile design that offers the ability to fit into smaller spaces than a large air cooling solution and comes with performance to match the best full-size air heat sinks on the market. This lower profile design does not come with the weight penalty associated with the large air cooled thermal solutions giving you some piece of mind if you transport your rig around on a regular basis. The inlet fittings come out the side of the reservoir and swivel both left and right. The coldplate has an application of thermal paste already applied so you don't have to worry about getting the correct application if you just use the "blob and go" method of TIM application. The pump assembly is controlled via a three pin power connection that can go either on the motherboard's CPU fan header or to a three pin to four pin wire adapter. The attachment method is visible in this set of pictures. The hold-down mechanism uses a series of notches in the retention ring that lock into place on the H70 when you tighten it down.




The use of fittings that swivel is a huge improvement over the tubing attachment method used on the Corsair H50. This means pretty much any combination of case and cooler can be accommodated so you do not end up with a kink in the non-permeable tubing or having any undue pressure on the motherboard or socket. Swivel to the left or right to fit the H70 into place.



The fans used by Corsair are 120mm x 25mm fans that run between 2000 RPM and 1600 RPM depending on whether you have used the included inline resistors or not. At 2000 RPM, the fans push just over 62CFM of air at 31.5 dBA. Static pressure is what helps the fans push airflow through a radiator. The included fans specifications show that the fans used have 1.8 to 2.3mm H2O worth of static pressure, higher than the Noctua NF-P12 fans used on the NH-U12P SE2. But that added static pressure and fan speed means the noise penalty is greater. When you knock the fans down to 1600 RPM with the supplied adapters, the airflow drops to 50.35 CFM, still pretty decent.



When you put the H70 and H50 Hydro series cooling solutions side by side the differences between the two are pretty easy to see. The tubing on the H70 is much shorter than the tubing on the H50 meaning an easier installation. The radiator looks to be pretty close to twice as thick, offering more surface area and liquid capacity.



The pump assembly is an area where the differences are also easy to spot. The pump/heat exchanger on the H70 is literally half the height of the pump on the H50. What this does is again give you more flexibility in the installation. The added depth of the H70 radiator with its two 120mm fans makes this a necessary change. The wiring to power the pump is another area of change. The H50 has a braided covering on the power supply wiring making it the more attractive wiring package. The surface prep on both heat exchangers is fairly coarse but it is flat.



Once installed in the system, you can see just how much room the radiator and dual fans take up in a full tower chassis. You can orient the H70 one of two ways. Taking the air in the case and pushing it out or pulling in air from outside the case and exhausting inwards. The exhaust-out solution dumps the heat load out of the case at the cost of using warmer case air to cool the radiator. The preferred solution from Corsair is to use the cooler from outside the case. The down side to this is you need to reconfigure the case airflow to compensate for this heat dump into the case. Perhaps by installing one or more top exhaust fans.


Let's see if the H70 can unseat the current king of the hill, the NH-D14.


Cold Plate Material
Fan Specs
2 x 120mm, selectable 2000RPM or 1600RPM
Radiator Material
Low-permeability for near-zero evaporation
24 Months





All information courtesy of Corsair @


Finding out how the Corsair H70 performs is the object of this exercise. Therefore, I will be making a comparison of the CPU temperatures in both idle and loaded states. Comparisons will be made while the CPU is at stock voltage and clock speed, as well as when the CPU is overclocked and 'over-volted'. This will help to show what kind of cooling performance this cooling solution from Corsair has to offer as compared to other socket 1366 compatible high-performance cooling solutions. These cooling systems will be tested head-to-head as they are delivered from the manufacturer. I could throw in a bunch of testing variables, but it is not reflective of what the products are capable of in "as-delivered" states. To test the idle temperatures, I will allow the computer to stay in an idle state for 30 minutes and take the idle temperature at this point. For the load testing, I will use Prime95 version 25.11 and choose the blend testing and allow the processor and memory controller to heat up to their maximum temperatures. The time frame is a four-hour run to allow the temperature to peak - usually at or around the 14K test. I will use Real temp 2.7 to take the high and low temperatures and average the temperatures generated over the four cores as my reported temperatures.

Testing Setup:


Comparison Heat sinks:







The H70 delivers nothing but excellent cooling in both the stock and overclocked tests. The results put this cooler right in line with some of the best air cooling solutions on the market. When the clock speeds were ratcheted up, the only cooler that delivered better results was the NH-D14. That being said, it all comes down to capacity when you start pushing the clock speeds and voltages higher than the range we normally test in. The only cooling solution (save a custom water loop) that allows my DO stepping to run Prime 95 stable at 4.2 Ghz, has been the NH-D14 from Noctua. While the Vantaqe ALC was good, it reached the break-even point at 4.0 Ghz with temperatures in the mid 70's Celsius. The break-even point I use as a gauge is where the aftermarket cooling solutions average temperatures reach and exceed the load temperatures of the stock cooling solution with the CPU running at stock speeds and voltages. In this case, 71 degrees Celsius. The NH-D14 reached an average of 70 degrees Celsius in my Prime 95 testing at 4.2Ghz. To see if the H70 was up to the challenge I pushed the clock speeds up as high as the temperatures would allow to see if it could indeed handle the load at 4.2Ghz. The H70 from Corsair still broke through the 70 Celsius barrier and managed to keep the processor in the mid 70's Celsius only up to 4.16 Ghz, just short of the 4.2 Ghz mark I was aiming for. A little bit of a letdown, but at 4.0 Ghz the H70 stays below the 70 degree Celsius threshold. The performance of the H70 versus the H50 shows that the larger radiator and dual fans do make a serious improvement in the cooling performance delivered by the H70.


The good news is that the Corsair H70 is a hell of an improvement over the H50. This is not just a re-skin with a larger radiator. The whole assembly has been rethought in partnership with Asetek to deliver cooling performance on par with and better than most of the high-end after market cooling solutions available today. You get a larger radiator for more cooling "capacity", you get not one but two fans for use in a push-pull configuration and a new pump/waterblock assembly that combine to get within striking distance of the NH-D14. In both the stock and overclocked testing, the H70 delivered results that were better than the H50 and both the entries from CoolIT, the ECO and the Vantage. When the screws were ratcheted up even higher than our baseline testing, the H70 delivered temperatures that were reasonable. What I mean by reasonable is that the overclocked numbers are close to what the stock Intel cooling solution delivers at full load at stock speeds (in this case, right around 70 degrees Celsius). Hey, if the stock cooler keeps the CPU at that temperature at full load stock CPU speeds and voltages, then running almost 1.5Ghz faster at the same temperature can't be all bad now can it?

With both fans running full speed ahead, the noise generated is not what could be considered loud. Of course my interpretation of loud may be clouded by the years of over-the-top loud cars and stereos. But putting it in perspective for me it is that it is not as noisy as the case fans used in the test case or the fans on the video card. Using the fans with the included low speed connector to drop the fan speed to 1600 RPM allows the fans noise signature to be further reduced. Just like most high end cooling solutions, the H70 is compatible with all of the current AMD and Intel sockets. This means pretty much any and all current systems can take advantage of this cooling option from a lowly four core up to the latest six core CPU's. The low profile pump assembly is both flexible in its installation orientation and easy to install. The low profile pump design allows the use of pretty much any aftermarket memory modules in your system because it does not hang over the DIMM slots. If you want the latest in super tall memory modules then go for it, the H70 won't be the reason you can't use them. The H50 was limited in how the pump assembly could be oriented and could cause some clearance issues in smaller form factor cases due to the way the lines exited the pump. Corsair and Asetek have resolved the problem on the H70 by making the line set swivel where it enters and exits the pump head.

If you look at the current price point, the Corsair H70 is offered at a point reasonably close to what a good high end air-cooling solution goes for (once you add in the cost of a pair of decent fans). For instance, a Thermalright TRUE goes in the neighborhood of $60.00 and once you add in two high CFM fans at 15 bucks apiece, you get to 90 dollars really quick. On the other hand, the Noctua NH-U12P SE2 can be had for about $75. It's just that when the screws and voltages get turned up that the two fall off and give you the NH-D14 as the true comparison again at 90 bucks. Pricing is on the higher end of the spectrum but capacity does come with a price tag. That tag is higher than a high-end air cooling solution but lower than a budget entry into custom water cooling.

All things considered the Corsair H70 is a product that hits the mark. It delivers excellent low-noise cooling in a maintenance free package for those who want to explore liquid cooling without the fears of having to build a custom setup.