3DMark05
Two 512MB cards and three 256MB cards are tested with ubiquitous 3DMark05. Five cards and only three visible lines? The explanation lies with the lack of impact a larger framebuffer has on performance. For example, compare the results from PowerColor's 512MB X800 XL to those obtained by a 256MB-equipped version. For all intents and purposes, and taking into account that the PowerColor's line is largely hidden behind the red of the 256MB card, there's not a great deal of performance benefit to be had here. It makes implicit sense when you consider both 'XL cards run at identical frequencies.
One would think that adding in 4x AntiAliasing and 8x Anisotropic Filtering would be reflected in a higher benchmark result for the 512MB PowerColor card. Not so, evidently. The GPU-bound test looks a treat at 1600x1200 4x AA/8x AF, yet that resolution and setting still isn't generating enough workload to swamp a 256MB card's framebuffer. GPU speed is greater concern with games/applications that rely on copious amounts of shading, so that's precisely why a RADEON 256MB X850 XT PE is significantly faster.
