The recently released Lost Coast episode of Half-Life 2 has upgraded the Source engine to allow High Dynamic Range (HDR) rendering, which provides a variety of special image-enhancing effects. The additional effects required Valve to raise the minimum system requirements for entry.
Valve's implementation of HDR incorporates blooming, along with enhanced HDR water reflection/refraction, HDR refraction (light), HDR skybox, HDR cube maps, HDR light maps and exposure control.
Half-Life 2: Lost Coast Test Settings
Two individual demos were created within the Lost Coast episode to examine how the MSI NX7800GT performs with HDR effects in the Source engine. A short demo at the start of the level examines the water reflection and refraction effects and the improved skybox and exposure control. The second demo commences within the dimly-lit Monastery and ends with the Helicopter attack, which tests the blooming effect, refraction, cube and light maps, and lastly, exposure control.
Half Life 2: Lost Coast - nv_rocks Test Results
This scene taxes shader performance and the NX7800GT is able to handle both the 1024x768 and 1280x960 resolutions without much of an impact. At 1600x1200, the frame rate can drop to the low 20's where the animation may stutter during movement.
Half Life 2: Lost Coast - nv_monastery Test Results
As expected, indoor areas proved to be less taxing on the NX7800GT as performance improved over the first timedemo sequence. The battle within the monastery at the top of the cliff is a spectacular event with HDR graphical effects - especially the lighting-related elements, which impact what the player can see within the arena. Again, increasing the resolution to 1600x1200 may be a bit too high for a single graphics card solution for the demanding player.
The overclocked scores paint a slightly different picture as the increased speed provide up to 7 more frames per second.