Cooling a modern quad-core processor, which has hundreds of millions of gates switching at frequencies north of two or even three gigahertz, is no trivial task. That's especially true for PC enthusiasts who enjoy pushing their processors past stock frequencies. Instead of keeping just one core in check, all four need to be stable at a given clock speed. As the number of cores increases, so do the odds that one will require extra voltage to keep up with the others, making a good cooling unit even more important.
A typical CPU cooler uses heatpipes to transfer heat from a large, solid metal base to an array of thin, metal fins. For several years now, this approach has yielded better results than one-piece units whose fins rise up from the cooler's base. Heatpipes have also allowed cooler makers to build massive towers of cooling fins, providing room for larger fans than were feasible with older designs. This brute-force approach relies on plenty of airflow and a large surface area to achieve the best results.
Interestingly, water cooling actually works in much the same way. A water block takes the place of the metal base found on air coolers, circulating coolant though internal channels to pick up as much heat as possible from the processor. Water-filled plastic or rubber tubing takes the place of a metal heatpipe, directing coolant to a radiator that transfers excess heat to the surrounding air. A powered pump pushes coolant through the system, and fans are typically used to generate airflow through the radiator.
Air and water cooling are similar in principle, but the added complication of routing coolant tubing, securing connection points, and mounting a radiator and fan typically makes water-cooling units much harder to install. The cost of individual parts for even a basic water-cooling system is much greater than what you'll pay for an equivalent air cooler, too. However, CoolIT Systems has introduced an all-in-one Domino ALC water cooler that costs about as much as a high-end air-based unit, and should be much easier to install than a typical water-cooling setup. I wouldn't be a case and cooling enthusiast if I didn't jump at the opportunity to test this new Domino. To face it, we've rounded up a top-notch air cooler from Noctua, a more traditional and affordable air tower from Kingwin, and a stock Phenom II heatsink. Let's see how each handles a Phenom II X4 940 at stock and overclocked speeds.
Kingwin's Revolution RVT-9225 HDT
Heatpipe tower goodness on the cheap
I've been using the Kingwin Revolution RVT-9225 Heatpipe Direct Touch as the CPU cooler in our enclosure test system for a while now. At $30, it's cheaper than most tower heatsinks but a bit more expensive than basic units.
The Revolution's design is typical of cooling units that have been around since the tower heatsink became popular. Three U-shaped copper heatpipes connect to 45 aluminum fins on one side, pass through a base at the bottom of the tower, and then reconnect to the fins again on the opposite side. With this approach, the Revolution is able to maintain a slim profile even with a fan attached.
Although the RVT-9225 is compatible with LGA775 and AM2/3 sockets, it doesn't come with retention hardware for Intel's new LGA1366 Core i7 socket. Kingwin doesn't sell Core i7 retention hardware separately for the RVT-9225, either.
The Revolution's LGA775 retention bracket does allow you to change the cooler's orientation in 90° increments, making it easy to direct airflow toward exhaust ports at the rear or top of an enclosure. However, the AM2/3 retention hardware isn't as flexible. The Socket AM2/3 retention clip orients the cooler's path of airflow parallel to the socket's retention tabs, and while it's possible to flip the cooler 180° to adjust the direction of airflow along that path, you can't rotate the cooler 90°. With the Asus M3A32 MVP Deluxe motherboard we used for testing, the Kingwin's airflow can only be directed up or down in a traditional tower enclosurenot toward the front or rear of the case.
Airflow is provided by a 92 mm plastic fan with seven blades. The fan is secured with soft rubber fasteners to keep vibrations from generating extra noise. A four-pin power connector should also help to keep noise levels low by allowing the motherboard to tune fan speeds based on CPU temperatures.
The Heatpipe Direct Touch portion of the Revolution's name is well-deserved. Kingwin has shaved down the heatpipes to match the contact plane of the rest of the cooler's base. Soldered joints between the pipes and base should ensure efficient heat transfer, allowing the heatpipes to channel heat directly from the CPU and from the surrounding heatsink base.
Mounting the Revolution was easy thanks to the fact that it clips right into AMD's standard Socket AM2 retention bracketno motherboard removal is necessary. The Thermaltake Spedo enclosure pictured above is particularly expansive, so it's hard to judge the Kingwin cooler's size in context. At 5.25" tall, 3.75" wide, and 3" thick, the Revolution is only a moderately-sized tower. It should fit inside most mid-to-full tower cases and be compatible with most motherboards. However, if your mobo has larger heatsinks around the socket or if you run taller memory modules, you'll want to pay attention to the height of the Revolution's bottom fin, which sits 1.4" from the base of the motherboard.