Half-Life 2: Lost Coast

The Half-Life 2: Lost Coast tech demo is quite a different story, although it produces a rather ambiguous picture of the graphics cards’ performance. In the first two resolutions, the speed of the ASUS card differs but little from that of the Radeon X1900 XT, whether full-screen antialiasing is on or off, but the latter is suddenly ahead in 1600x1200, especially at the “pure speed” mode where the memory subsystem performance is of little importance. The gap between the two cards amounts to 30% in this case! Can it be that the 48 pixel processors of the new chip from ATI are necessary for one resolution only? Maybe it’s the enlarged Z-buffer rather than the pixel processors? It may be so since the resolution of 1600x1200 is the only one where the Radeon X1900 XT outperforms the GeForce 7800 GTX 512 that has an ability to process 32 Z-values per clock cycle. The Radeon X1900’s shadow mapping acceleration feature may have played some role here, too.