In order to build a Quad SLI system, you're going to need a high quality power supply unit to ensure that the system gets adequate power. NVIDIA has compiled a list of certified power supplies for Quad SLI with a pair of GeForce 7950 GX2's and you can find it on the SLI Zone portal
. The PSU with the lowest power rating on NVIDIA's certification list is 700W - there are certified models from Tagan, Thermaltake and XClio.
There are also a couple of supplementary power supply units from FSP Group and Thermaltake, designed to provide a dedicated power source for the graphics subsystem. While the supplementary power supplies are a good way to boost an existing power supply unit, they require a second mains power connector, meaning more cable mayhem behind your PC.
We recommend using one of the larger dedicated power supply units, especially if you are considering overclocking the system as well. We used Tagan's 900W unit in the Scan 3XS Panther
; this time around we are using PC Power & Cooling's Turbo-Cool 1KW unit. It was the loudest part of the system we built and we definitely recommend using some sound dampening if you're building a Quad SLI machine yourself.
We used Cooler Master's Mystique 632 Black chassis as the base of our system. It's not an expensive case at around £90, but one downside is the lack of a slide-out motherboard tray. In order to install PC Power's Turbo-Cool 1KW unit, we had to remove the top USB/headphone ports because of the size of the PSU behemoth.
Since NVIDIA recommends using the fastest CPU possible, we decided to use Intel's Core 2 Extreme X6800 processor in the only Conroe-ready motherboard supporting SLI available - the Asus P5N32-SLI SE. Installing the P5N32-SLI SE wasn't too much trouble - we installed the Zalman CNPS9500 heatsink and 4x512MB of Corsair's XMS2-5400C4PRO memory modules (these were later changed for a pair of 1GB Corsair XMS2-6400C3 modules) before installing the mobo in the Mystique.