Left4Dead

Left 4 Dead is a cooperative first-person shooter video game. It was developed by Turtle Rock Studios, which was purchased by Valve Corporation during development. Set during the aftermath of an apocalyptic pandemic, the game pits its four protagonists - dubbed "the Survivors" - against hordes of the infected. There are four game modes: a single-player mode in which allied characters are controlled by AI; a four-player, co-op campaign mode; an eight-player online versus mode; and a four-player survival mode. In all modes, an artificial intelligence (AI), dubbed the "Director", controls level pacing and item spawns, in an attempt to create a dynamic experience and increase replay value.

Left 4 Dead uses Valves Source engine which is DirectX 9 based. For this reason there are no noticeable differences in image quality between Windows XP and Vista/7 however the same cannot be said of performance. As the results show, when we run the game at 2560x1600 with 16xQCSAA and 16x anisotropic filtering we receive a small boost in performance when using a newer operating system. Additionally, as we have seen a few times Windows 7 offers slightly higher framerates than Vista.