|Corsair Hydro H70 Liquid CPU Cooler|
|Reviews - Featured Reviews: Cooling|
|Written by David Ramsey|
|Monday, 07 February 2011|
Page 5 of 6
Testing and Results
For this test, I used the following heat sinks in addition to the Thermaltake Jing:
For heat sinks without a stock fan, I used a Thermalright TR-FDB-12-1600 fan, which puts out 63.7CFM at 28dBa according to Thermalright. This mid-range fan provides good air flow and reasonable noise levels. For "apples to apples" testing, where each heat sink is tested with the same fan, I used a Delta AFC1212D. This high-performance PWM fan is rated at 113CFM at a claimed 46.5dBa at full speed...which means that while it moves quite a bit of air, it's very loud.
The Intel Core i7-950 I used in this test runs much hotter than the Core i7-920 I'd used previously. At 1.35 volts, with a BCLK of 175Mhz, the 4,025Mhz CPU pumped out enough heat to stress the very best heat sinks. AIDA64 would report throttling once any single core reached 100 degrees Celsius; any throttling resulted in cancelling the test and recording a "FAIL". Although this overclocked and overvolted Core i7-950 represents an extreme, these are expensive, high-end heat sinks.
The chart below summarizes the results with the stock fans (hotter temperatures towards the top of the chart, and cooler temperatures towards the bottom). The twin-fan units (the Cooler Master V6 GT and the Corsair H70) have a real advantage here, since their dual fans move more air than the stock single fan of any of the other units. The Corsair H70's fans at their default 2,000RPM level move a lot of air together, but also generate a fair amount of noise. At the 1,600RPM level achieved with the in-line resistor cables, the noise level is much reduced, with a relatively minor performance hit. While Corsair says the stock H50 fan provides about 50CFM, they do not provide any specifications on the H70 fans other than their dimensions, so the official air flow, static pressure, and noise levels are a mystery, which is annoying if you are considering replacing the fans.
Stock Fan Tests
With its dual, high performance fans (according to Cooler Master, each fan is rated at 93CFM at full speed, for an aggregate airflow of over 180CFM) the Cooler Master V6 GT takes the lead here, keeping the blistering hot Core i7-950 4.1 degrees Celsius cooler than the H70 with its fans running at full speed. The Cooler Master H70 also benefits from dual fans, but perhaps they're not moving quite as much are as the V6 GT fans (we don't really know since Corsair does not provide airflow numbers). Dropping the H70's fan speed to 1,600RPM with the included resistor cables makes the system much quieter at the cost of 2.4 extra degrees of processor temperature.
What's interesting in this chart is the 5.3-degree "break" between the Coolit Vantage A.L.C. and the Corsair H70, which neatly separates the coolers into "lower performance" and "higher performance" groups.
Delta High Speed Fan Tests
With the Delta high-speed fan, our lineup changes. The Coolit ECO A.L.C. moves from the bottom to the chart to just beyond mid-pack, improving by almost 11 degress. The Prolimatech Super Mega and Thermalright Venomous X jump to the to lead, and the Corsair H70 drops back a few places, although its actual performance is very slightly (0.6 degrees Celsius) better. This is something I've seen before when replacing a dual-fan cooler's stock fans with a single fan: the performance advantage of even very noisy, high speed fans is minimal if it exists at all. Note that in this scenario, the Coolit ECO A.L.C. with its much thinner radiator actually performs better than the H70. I think the 48mm-thick radiator of the H70 works best with dual fans to push the air through all those fins. (Again, it would be nice to know the air flow and static pressure specifications of the included fans.)
In this chart, there's a 4.8-degree "break" between the Coolit ECO A.L.C. and the Cooler Master V6 GT. In this "apples to apples" comparison, the three top-performing air coolers are obviously in a class of their own. While all-in-one water cooling kits are making progress, Big Air still has a significant advantage in this scenario.