Overclocked Test Results

Here it is, the only section that matters in the world of high-performance overclocking and aftermarket CPU coolers. After all of our stock testing was complete, we removed the 2.66GHz Intel Core i7-920 processor and spend an hour lapping it flat with super-fine 1200 grid wet-sanding paper on a thick piece of glass. Once the Integrated Heat Spreader (IHS) exposed the copper finish, we switched to ultra-fine 2000 grit wet-sanding paper. To add a final buffing finish, the surface was wet-sanded with ultra-fine 2500 grit and then polished with liquid finishers. When the Core i7-920 was reinstalled into the X58 test platform, the voltage was raised to 1.35V and pushed to a moderate 3.6GHz overclock. A much higher overclock was available, but because of failure or instability risks, Benchmark Reviews tests at the most stable speed possible to avoid crashes and potential test failures. Remember, they all must pass testing, or the testing must be redone completely.

The core temperatures all immediately increased by nearly 20°C across the entire collection, even with the Yate Loon D12SH-12 huffing and puffing. All kits used either an included or aftermarket bolt-through kit for mounting the cooler and creating good contact pressure. After each test run was completed (usually about one hour), the cooler was removed and the contact spread was inspected before being cleaned and re-installed for another test. Doing this revealed an peculiar trend, which make the distinction between LGA775 and LGA1366 performance more understandable.

Because of the slightly spread-out core placement on a Core 2 Quad or Duo processor, most triple-piped HDT cooler would make directly-aligned contact with the cores through the IHS. However, when it comes to the Core i7 series, the processor cores line-up better with four-piped HDT coolers (or at the outer edge of the center heat-pipe in the three-piped HDT cooler). Conversely, coolers with a solid base are not effected by either platform, so long as they're big enough to saturate the contact surface. Making matters a little more complicated is the orientation of the Core i7 processor series, which is restricted to comply with the Intel-designed horizontally-aligned rectangle shape (not square like LGA775 processors). The 32mm tall by 35mm wide Core i7 processor is more sensitive to how a cooler is mounted to it, and care must be take to ensure the IHS is fully covered.

The overclocked Intel Core i7-920 processor helped to separate our large collection of LGA1366 cooler by more than 10°C between them. Benchmark Reviews is confident that these results match those of users with the same system and configuration, but because our tests route the video card and X58 Northbridge through a water-cooling system to avoid radiant heat corruption in our results, your own results will be slightly higher. In order of final performance, these are the Best CPU Coolers for the overclocked LGA1366 Core i7 platform:

All of the top performing CPU coolers have a few things in common, although some are better designed than others. The mounting system on the Prolimatech Megahalems uses an excellent bolt-through system with keyed alloy plates to ensure a perfectly centered cooler, similar to the Xigmatek Crossbow kit we use for other coolers. The Thermalright Ultra-120 eXtreme also uses a bolt-through kit, as does the Cooler Master Hyper Z600 and V8... so contact pressure is extremely high for all of these products. Half of our CPU cooler collection have very flat mirror finishes for the contact surface, whereas the other use Heat-pipe Direct Touch (HDT) technology. Every single one of these coolers have either large-gauge heat-pipes, or several pairs of heat-pipe rods integrated into the base. The Domino matches a flat polished surface to water cooling. In my opinion, every single product on this chart is an excellent cooler, but only the top few can be considered the Best CPU Cooler.

The Prolimatech Megahalems is the standout top-performer, with a total adjusted temperature of 37.73°C over ambient. Nearly three degrees away is the Thermalright Ultra-120 eXtreme and Xigmatek Thor's Hammer S126384. All three of these coolers are phenomenal performers, and deserve the title of Best CPU Cooler for the Intel Core i7 / LGA1366 socket.

The Titan FINRIR, all-copper Xigmatek S1284 prototype, Thermolab BARAM, CoolIt Domino ALC, Cooler Master Hyper Z600, and The Xigmatek Dark Knight S1283V are all trailing a few more degrees behind the leaders. All of these coolers will work extremely well in overclocked systems, and given the right circumstances might perform just as well. Some of these coolers will accept a second fan, further improving results, while other are limited to only one. Taking cost into consideration, the field can been reduced to only a few real contenders.

Although it performs within 9°C of the leader, the Cooler Master V10 TEC was not nearly as impressive as it looks. I was warned by Cooler Master that the TEC cooling technology only kicks in at higher temperatures, but I'm not clear on what that magic number is. If it didn't 'turn-on' during this test, I'm not sure when it will. Additionally, I wondered why they would make it wait for high temperatures, when even moderate temperatures deserve good cooling, too. The OCZ Gladiator Max, Noctua NH-U12P, Vendetta 2, and Spire TherMax II all finish out the high-performance group of coolers, and trail up to 10°C behind the leader.

The Cooler Master V8 does well enough, but the limited fan potential locks it down to a single 120x120x25mm unit. It the V8 wasn't so large, I might be a little more forgiving, but since it occupies so much space I become more critical. Without fail, there's always an exception to the rule for one particular product. For this section, it's the Zalman CNPS9900 LED. Sure, it's unfair to judge the CNPS9900 against a collection of larger Yate Loon cooled products, but the integrated SuperFlo-bearing 92mm fan sure manages to hold its own against the more formidable opponents. I didn't add the Zalman CNPS9900 LED cooler into these results to be cruel, but instead show how a small, well-designed cooler can compete with the larger products if the manufacturer does their engineering homework.

In the next section, I offer my final thoughts on the future of CPU coolers.

<< Previous Page - Next Page >>