CPU: Intel Core i7 Extreme Edition 965

Most of us prefer to seek the best possible value, using overclocking as an excuse not to buy elite-class (and often over-priced) components. After all, with the exception of a few minor features, aren’t all Core i7 processors really the same, save an unlocked multiplier? The only way to test that theory would be to buy the best, which is something many $5,000 PC builders would do anyway and consider the differences between it and previously-tested lower-cost parts.

Read Customer Reviews of Intel's Core i7 Extreme Edition 965

The two documented differences between Core i7 Extreme and its siblings are its unlocked multiplier and an increased QPI-link rate of 6.4 GT/s, compared to 4.8 GT/s for cheaper versions. But while every model of Core i7 is also differentiated by rated speed, what’s not documented is how well each model is cherry-picked for the task.

All Core i7 processors come from the same process, and while Intel has been known to determine the best parts by testing, there is simply no way of knowing how much difference separates the lowest- and highest-end models. We hope that choosing the highest-end model will allow us to reach the highest overclock, but there is always the possibility that the lowest-end models of one batch might actually overclock better than the highest-end models of another. The only way to know how well any processor will respond to an overclocking effort is to test it, since each processor is unique.

Intel includes a higher-capacity, all-copper cooler with its Core i7 Extreme. This would be a great accessory for budget overclockers if available separately, but our overclocks are a little more “extreme” than what the Extreme cooler is designed to cope with.

CPU Cooling: Custom-Liquid Configuration

Setting up a liquid-cooling system should be easy with a partner as large as Newegg, but the i7 water cooling market is still young enough that a complete kit still isn't available for the Core i7 Extreme. Also, since we had to return our parts to Newegg, we couldn’t simply drill holes in the case to mount various components. Instead, we had to piece together our cooling system with a variety of parts, beginning with the pump-and-reservoir assembly of Cooler Master’s Aquagate Max.

Read Customer Reviews of Cooler Master's RL-HUB-KBU1-GP Water Cooler

We scoured the Web, comparing every pump-and-reservoir option Newegg offered, and the easy installation and a flow rate of 450L/H made the Aquagate Max the best fit for our application. A few testers had claimed the kit’s fans and water block were inadequate, but we planned to replace those anyway.

In fact, because we had selected a specific case for its triple-fan-radiator support, our first move was to replace the two-fan Cooler Master unit with a three-fan model from Swiftech. We’ve long appreciated the capabilities of its MCR320-QP Quiet Power radiator , and this is also the only three-fan model Newegg carries.

Increased airflow usually comes at the expense of added noise, but a well-designed fan provides the best of both worlds. Rated at 63.7 CFM and 1,600 RPM, fluid-dynamic-bearing technology and optimized blades keep the Scythe S-Flex SFF21F below its 28 decibel peak noise level under typical operating conditions. With nearly as much capacity per fan as two of Cooler Master’s fans, three SFF21Fs should prove more than sufficient for our CPU-cooling needs.

The only part we couldn’t get from Newegg was a liquid-cooling water block for LGA-1366 processors. After waiting three months for the requisite component to show up at retail, we gave up and used our own means to obtain the Apogee GTZ LGA-775 water-block assembly and LGA-1366 bracket. The combination must be in high demand, because several companies that had offered pre-configured Apogee GTZ LGA-1366 assemblies were out of stock.