Liquid Cooler Lineup: Intel, Corsair, MainGear Tested

In our first overclocking test, we push the CPU's maximum frequency up to 4.13GHz from a 3.6GHz turbo mode (a gain of 14.7 percent). We also increased the core voltage to 1.35v. The H80 and H100 were set for 'Quiet' mode.


Here, the LC2011RTS and Corsair H80 are essentially tied, as are the Epic 180 and H100. Intel's cooler spins up sharply at this point; fan RPM rises to ~2200 up from 800.

For our second overclocking test, we increased the CPU to 4.5Ghz, a further gain of 8.9 percent (25 percent faster than the original Turbo Mode). This modest gain required an additional 0.02v (1.37v CPU). Our CPU apparently tops out right about here -- we weren't able to stabilize the chip at 4.67GHz, no matter what combination of voltages and multipliers we tested.

The Corsair fans were set to 'Performance' for this test.


Intel's cooler wasn't able to stabilize the chip in Prime 95 during our peak test; the program crashed within minutes. The H80 and H100 fared better; the H80's temperatures fell slightly thanks to the increased fan speed while the H100's thermals only increased modestly.

The Epic 180's temperatures puzzled us until we talked to Maingear and realized that the cooler's fan was spinning at the same speed no matter what the CPU load was. When we turned off BIOS control and set the fan to full speed, temperatures dropped significantly. Here, the 180mm design pays off; 1200 RPM fans are generally quiet regardless; a 180mm fan at 1200 RPM is nearly silent.

While these numbers are for the entire system, the CPU is the only component whose power draw we've adjusted. At 4.5GHz, the chip is dissipating too much heat for the single-fan RTS2011LC to keep up. This is part of why six-core chips from AMD and Intel really aren't the best options if you care about overclocking and want best-case single-thread performance. If you know you won't need more than four cores / eight threads, you'll likely get better overclocking out of a quad-core Sandy Bridge.

Noise:

One of the supposed advantages of water coolers is that they're quieter than standard heatsink+fans. Our normally trusty decibel meter isn't capable of picking up sounds below 50 dB, which made it impossible to objectively measure noise levels between the various coolers, but we have a few subjective observations to share.

First, the much-touted aural advantage of liquid coolers is undercut by at least a little pump noise. Even if LC's are quieter on an absolute scale, replacing a modern heatsink+fan with a liquid cooler means substituting the quiet sound of low-speed airflow for the quiet sound of a small motor. Which of these suits you better is a matter of personal preference.

In every cooler we tested, the pump noise was actually louder than the fans when the CPU was idling. Maingear's Coolersaurus tied Intel's RTS2011LC for quietest subjective cooler when the system was idling and took home the bacon as far as quietest overall design thanks to the Radiator That Ate Manhattan. The H100 and H80 followed it, as one would expect. The H100 is quieter than the H80, even at the same fan speed, thanks to the larger radiator that sits two fans beside each other rather than doubling them up one behind the other.