[nextpage title=”Introduction”]

After reviewing several CPU air coolers, it is time we to test the top-shelf liquid cooling solution from Corsair: the H70. It is a complete sealed system, with easy installation and no maintenance. Let’s see if it is really worthwhile picking this system over high-end air coolers.

Traditionally, water coolers are sold as individual components: you have to buy a radiator, block (or blocks, if you want to cool other parts othar than the CPU, like the GPU and the chipset), hoses, pump and reservoir. This kind of system is obviously targeted to the ultra-enthusiast user, since installing and setting up the system is not that easy. Some time ago, however, manufacturers started selling sealed systems, where the product comes preassembled and installation is almost as easy as regular air cooler. The H70 is one of these products.

The H70 box is big, made of hard card paper, as you can see in Figure 1.

Corsair H70Figure 1: Package

In Figure 2, you can check the content of the box: the radiator/block system, two 120 mm fans, manual, and hardware installation parts. As you can see, the radiator, hoses and block are preassembled and sealed, which means the cooling fluid comes already inside the system and there is no need for maintenance.

Corsair H70Figure 2: Accessories

In the next pages, you will see this cooler in detail.[nextpage title=”The Corsair H70″]

In Figure 3, we can see the CPU block. It is actually a device intended to transfer the heat from the CPU surface to the fluid circulating inside the hoses. In this model, the pump that makes the cooling fluid (usually water mixed with an anti-corrosion additive) to circulate in the hoses is integrated in the block. The cable you see in Figure 3 are to power this pump.

Corsair H70Figure 3: CPU block with integrated pump

In Figure 4, you see the copper base of the block. The thermal compound comes preapplied, which is more common to see in cheap coolers. The surface covered by the thermal grease is bigger than most CPUs, so it may make some mess during its installation. It would be better if Corsair has included a tube of high-quality thermal compound instead of preappling it.

Corsair H70Figure 4: Base of the CPU block

In Figure 5, you see the radiator. Like it happens on a car radiator (it also looks like one), its purpose is to transfer the heat from the liquid to the air that passes though it. This radiator has installation holes for two 120 mm fans.

Corsair H70Figure 5: The radiator

The two 120 mm fans, shown in Figure 6, are simple, with no fancy colors, just plain black. They are not PWM-compatible and there isn’t any anti-vibration mechanism.

Corsair H70Figure 6: The fans

[nextpage title=”Installation”]

The installation of the Corsair H70 is almost as simple as an air cooler. First you must attach a metal frame on the motherboard, screwing it to a backplate that goes on the solder side of the motherboard. Then you need to put the CPU block inside the frame, turn it a little bit in order for it to be locked at the tabs present on the frame, and then fasten the four screws.

To install the Corsair H70 your case must have one 120 mm fan opening at its rear side (if your case comes with a fan there, it must be removed), since the rear fan must be installed on the radiator and, at the same time, on the rear panel of the case. The second fan, which goes on the front side of the radiator, is easy to install.

The manual recommends to install the radiator fans as intake (i.e., blowing air from the outer side on the radiator), in order to get the best performance, so this was the way we installed it during our tests. This recommendation has some logic: if the fans take the colder external air to cool down the radiator, the watercooler will perform better. But you have to keep in mind that, depending on the ventilation of your case, this may heat other internal components, like the video card and the motheboard voltage regulator circuit. This setup will probably work better if your case have an exaust fan or fans at its top panel.

To finish the installation, connect the pump and the fans to the motherboard power connectors or to a fan controller.

Corsair H70Figure 7: The Corsair H70 installed in our case

[nextpage title=”How We Tested”]

We tested the cooler with a Core i7-860 CPU (quad-core, 2.8 GHz), which is a socket LGA1156 processor with a 95 W TDP (Thermal Design Power). In order to get higher thermal dissipation, we overclocked it to 3.3 GHz (150 MHz base clock and 22x multiplier), keeping the standard core voltage (Vcore), which was the maximum stable overclock we could make with the stock cooler. Keep in mind that we could have raised the CPU clock more, but to include the stock cooler in our comparison, we needed to use this moderate overclock.

We measured noise and temperature with the CPU idle and under full load. In order to get 100% CPU usage in all threads, we ran Prime 95 25.11 (in this version, the software uses all available threads) with the "In-place Large FFTs" option.

We compared the tested cooler to the Intel stock cooler with a copper base (included with the CPU), as well as with other coolers. Note that in the past, we tested coolers with a socket LGA775 CPU, and we retested some "old" coolers with this new methodology. This means you can find different values in older reviews than the values you will read in the next page. Every cooler was tested with the thermal compound that accompanies it.

Room temperature measurements were taken with a digital thermometer. The core temperature was read with the SpeedFan program (available from the CPU thermal sensors), using an arithmetic average of the core temperature readings. During the tests, the left panel of the case was open.

The sound pressure level (SPL) was measured with a digital noise meter, with its sensor placed 4" (10 cm) from the fan. We turned off the case and video board cooler fans so they wouldn’t interfere with the
results. This measurement is only for comparison purposes because a precise SPL measurement needs to be made inside an acoustically insulated room with no other noise sources, which is not the case here.

Hardware Configuration

Operating System Configuration

  • Windows 7 Home Premium 64 bit

Software Used

Error Margin

We adopted a 2 °C error margin, meaning temperature differences below 2 °C are considered irrelevant.

[nextpage title=”Our Tests”]

The table below presents the results of our measurements. We repeated the same test on all coolers listed below. Each measurement was taken with the CPU at idle and at full load. In the models with a fan supporting PWM, the motherboard controlled the fan speed according to core load and temperature. On coolers with an integrated fan controller, the fan was set at the minimum speed on the idle test and at full speed on the full load test.


Idle Processor

Processor at Full Load

Cooler Room Temp. Noise Speed Core Temp. Noise Speed Core Temp.
Intel stock (socket LGA1156) 14 °C 44 dBA 1700 rpm 46 °C 54 dBA 2500 rpm 90 °C
Cooler Master Hyper TX3 G1 14 °C 47 dBA 2050 rpm 33 °C 56 dBA 2900 rpm 62 °C
Zalman CNPS10X Extreme 14 °C 45 dBA 1400 rpm 27 °C 53 dBA 1950 rpm 51 °C
Thermaltake Silent 1156 14 °C 44 dBA 1200 rpm 38 °C 49 dBA 1750 rpm 69 °C
Noctua NH-D14 14 °C 49 dBA 1250 rpm 27 °C 49 dBA 1250 rpm 53 °C
Zalman CNPS10X Performa 14 °C 46 dBA 1500 rpm 28 °C 52 dBA 1950 rpm 54 °C
Prolimatech Megahalems 14 °C 40 dBA 750 rpm 27 °C 60 dBA 2550 rpm 50 °C
Thermaltake Frio 14 °C 46 dBA 1450 rpm 27 °C 60 dBA 2500 rpm 50 °C
Prolimatech Samuel 17 14 °C 40 dBA 750 rpm 40 °C 60 dBA 2550 rpm 63 °C
Zalman CNPS8000A 18 °C 43 dBA 1400 rpm 39 °C 54 dBA 2500 rpm 70 °C
Spire TherMax Eclipse II 14 °C 55 dBA 2200 rpm 28 °C 55 dBA 2200 rpm 53 °C
Scythe Ninja3 17 °C 39 dBA 700 rpm 32 °C 55 dBA 1800 rpm 57 °C
Corsair A50 18 °C 52 dBA 1900 rpm 33 °C 52 dBA 1900 rpm 60 °C
Thermaltake Jing 18 °C 44 dBA 850/1150 rpm 34 °C 49 dBA 1300 rpm 60 °C
GlacialTech Alaska 18 °C 43 dBA 1150 rpm 36 °C 51 dBA 1600 rpm 60 °C
Deepcool Gamer Storm 18 °C 43 dBA 1100 rpm 35 °C 48 dBA 1600 rpm 62 °C
Corsair A70 26 °C 56 dBA 1900 rpm 40 °C 56 dBA 1900 rpm 65 °C
Deepcool Ice Blade Pro 23 °C 45 dBA 1200 rpm 38 °C 52 dBA 1500 rpm 64 °C
AC Freezer 7 Pro Rev. 2 23 °C 47 dBA 1750 rpm 44 °C 51 dBA 2100 rpm 77 °C
Corsair H70 27 °C 60 dBA 1900 rpm 37 °C 60 dBA 1900 rpm 61 °C

In the graph below, at full load you can see how many degrees Celsius hotter the CPU core is than the air outside the case. The lower this difference, the better is the performance of the cooler.

Corsair H70

[nextpage title=”Main Specifications”]

The main features of the Corsair H70 Water cooler include:

  • Application: Socket LGA775, 1156, 1366, AM3, AM2+ and AM2 processors
  • Fins: Aluminum
  • Base: Copper
  • Heat-pipes: None
  • Fan: two, 120 mm
  • Nominal fan speed: 2,000 rpm
  • Fan air flow: 61 cfm
  • Maximum power consumption: not informed
  • Nominal noise level: 31.5 dBA
  • Weight: 1.8 lbs (820 g)
  • More information: https://www.corsair.com
  • Average price in the US*: USD 93.00

* Researched at Amazon.com on the day we published this review.[nextpage title=”Conclusions”]

The Corsair H70 watercooler did what we expected from it: it overperformed all the air coolers we tested to date.

However, cooling performance is not the only feature one looks when thinking about spending money buying a liquid cooling system. Good watercoolers must offer both performance and silence, and the H70 was not even close to be silent; actually it reached the same noise level as top-performance air coolers.

The twin 120 mm fans are very powerful and, as any powerful fan, make a lot of noise. We are used to complain about non-PWM fans on mainstream coolers, but in this case we are talking about a relatively expensive product targeted to users that want more than a mainstream product has to offer. On the other hand, we believe that some users will probably connect the fans of the H70 to a fan controller, so he or she can find a balance between performance and silence.

Because its great performance, better than any air cooler we tested to date, but with a noise level that was higher than we expected, the Corsair H70 liquid cooling system deserves the Hardware Secrets Silver Award.