The official launch of Nvidia's SLI graphics technology is almost upon us. Possibly the biggest event for PC Hardware this year, Nvidia have sparked tremendous interest. Today, Hexus.net have an introduction to the technology, including the two modes in which SLI runs (alternate-frame and split-frame rendering,) how the system is physically setup, including the inter-gpu link and what happens if you remove it mid-game! Benchmarks in Far Cry , Doom III and Half-Life 2 are also included, in what is the first part of Hexus' SLI coverage. From the article: "Currently, SLI allows you to accelerate rendering using two effective modes, which map to around four general cases of multi-GPU rendering. The first, SFR or split-frame rendering, has each graphics card render a portion of the screen, split horizontally. One card, the primary device on the PEG host, is responsible for the top section of the screen, the secondary device therefore responsible for the bottom. That situation is then load balanced. More on that shortly.

The second mode is AFR, or alternate-frame rendering. For each graphics device in the system, the driver round-robins the graphics commands and data to each device, forcing each device to render a frame in turn. For a dual-GPU SLI setup, each device renders a frame, waits for a frame, then renders a frame, ad infinitum. Interleaved with the second device doing the same, that's AFR in a nutshell."