Water-cool your PC

Water-cooling systems have three main parts: waterblock, pump, and radiator. The waterblock fastens onto your CPU or graphics processing unit (GPU), and cooling liquid circulates through its hollow interior to draw heat from the chip. The pump, either a discrete unit or part of the radiator or CPU-waterblock assembly, keeps the coolant moving. Finally, coolant flows through the radiator, which is cooled either actively (by fan) or passively (by sheer surface area). The principle's much the same as cooling a car engine. Hoses and fittings complete the hardware.

Water-cooling gear is sold in kits or as individual parts. We recommend kits for first-timers. Also, the system can be either fully internal or partly internal/ partly external. Internal systems are neater, but all the gear can overwhelm a case, blocking drive bays or slots. Internal/external systems overcome this problem by letting you place the radiator and perhaps the pump on your desk.

We opted for the latter and went with Zalman's Reserator 1 Plus, a premium rig that integrates pump, radiator, and fluid reservoir in a mammoth, passively cooled "Reserator" tower. The tower is big and expensive and could be mistaken for Darth Vader's air ionizer, but all the kit components are beautifully machined, and installation is easy. The system works with Pentium 4 Socket 478 or 775 PCs and most recent AMD-based PCs (Socket 462, 754, 939, or 940).

The pump moves coolant from the Reserator, through a hose that passes through a PCI-slot bracket, into the CPU waterblock, where it cools the processor. Another hose takes it to a second waterblock, where it cools the GPU. Finally, the liquid follows a third hose back out to the Reserator tower, where heat is dissipated through the tower's heavy aluminum fins.