Introduction

After over a year of waiting, Valve Software’s Half-Life 2 is finally here! Released at midnight yesterday, countless gamers have started playing and the buzz (unlike DOOM 3) has been pretty much unanimous: Half-Life 2 is a winner! Over the past 24 hours, we’ve been busy “working” on Half-Life 2, with the goal to determine which graphics cards run best with Valve’s latest shooter. We’re here today to present our preliminary results.

First things first, as we’ve said in the past, Half-Life 2 scales very well with older hardware. You don’t have to purchase the latest and greatest graphics cards from ATI and NVIDIA in order to achieve playable performance with good graphics, but if your goal is to reach 1600x1200 with all the eye candy cranked to the max, it’s highly recommended. Valve has designed Half-Life 2 to scale all the way back to DirectX 7 hardware and will automatically detect your graphics card and determine a recommended setting that’s suitable for casual gamers who aren’t into tweaking graphics settings. Eye candy used in Half-Life 2 hasn’t changed since our “GeForce FX DirectX 9 Performance” article, so we’ll include that chart again just in case you missed it:

Feature usage in DirectX paths
Feature	DirectX 7	DirectX 8	DirectX 9
Radiosity-Based Diffuse Bump Mapping	No	World, Displacements	World, Displacements, Viewmodel, Static Props, Dynamic Props, Non-Player Characters (NPCs)
Specular Bump Mapping	No	World, Displacements, Viewmodel, Static Props, Dynamic Props, NPCs (Reduced quantity than DirectX 9)	World, Displacements, Viewmodel, Static Props, Dynamic Props, NPCs
Detail Props (Procedurally-placed grass, rocks, etc. based on material)	No	Only near	Out further
Dynamic Shadows	Blobby	Sharp render-to-texture	Soft render-to-texture
Static Props (instanced models)	Medium Level-of-Detail (LOD) Some removed, No decals	High LOD	High LOD
Specularity	No	Yes (limited usage)	Yes
Dynamic Refraction	No	Yes (limited usage)	Yes
3D Skybox	Yes	Yes	Yes
Water	Transparent Textures	Pretty nice (with volumetric fog)	Damn nice (with volumetric fog)
Cameras/Monitors	In scene (if render targets are supported)	In scene	In scene
Volumetric Effects (Any smoke or fog)	Sparse	Yes (per-pixel lit)	Yes (per-pixel lit
Shader Function	Fixed-function (hardware T&L)	Assembly Vertex/Pixel Shaders (VS1.1, PS1.1-PS1.4)	DX9 HLSL Vertex/Pixel Shaders (VS2.0, PS2.0)
Displacement Maps (Terrain, cave walls, etc)	Medium res	Mid-to-High res (with diffuse and specular bump-mapping)	Full-res (with bump diffuse and specular bump mapping
Texture Resolution	Medium (256x256)	High (512x512)	High (512x512)
Texture Variety	Low	Full	Full

DirectX 7 path

Half-Life 2’s DirectX 7 path includes NVIDIA’s GeForce 256, GeForce 2 series, GeForce2/4 MX, and nForce, and the RADEON 7xxx series (with RADEON 9100 IGP and MOBILITY RADEON 9000/9100 defaulting to the DirectX 7 path as well).

Screen space effects are really simple.

No model decals

No detail props

No refractive water

Reduced decal visibility distance

No bumpmaps

Reduced model LODs

Reduced material mip level

DirectX 8 path

Among the cards included in the DirectX 8 path are GeForce4 Titanium series (including GeForce4 Go), GeForce FX 5200/5600/5700, and GeForce FX Go 5600/5700 series.

On some cards with poor fillrate, bumpmaps may be turned off in some scenes that use a lot of bumpmaps. At the moment, this is true for the GeForce4 Ti 4200 but we've worked with Nvidia to come up with a solution to reactivate bumpmaps on the 4200.

Water by default is refractive but does not have local specular.

Water has a hard edge when it meets the shore, volumetric fog is used for this. Its per vertex screen space effects are better than DirectX 7, but still simple.

Shadows are render-to-texture but are not supersampled to make them
look softer.

DirectX 8.1 path

Cards that use the DirectX 8.1 path include RADEON 8500/9100, RADEON 9000/9200, GeForce FX 5800/5900.

Water by default is refractive but does not have local reflections. If you activate local reflections on this card, it will occur in one pass as opposed to happening in 2 passes on DX8.0, which will make it cheaper from a fillrate perspective.

As in DX8.0, water has a hard edge when it meets the shore, volumetric fog is used for water. Its per vertex screen space effects are better than DX7, but still simple.

Shadows are render-to-texture and are supersampled to make them look
softer.

DirectX 9 path

Graphics cards that use the DX9 path include GeForce 6800 series, GeForce 6600 series, RADEON 9500/9600, RADEON X300/X600 series, RADEON X800 series, RADEON 9700/9800, MOBILITY RADEON 9600/9700, and MOBILITY RADEON 9800

Water by default is refractive with local reflections from world geometry.

Water refraction realistically refracts the geometry beneath the water (when looking into the water) based on the depth of the geometry in DX9.

There is a special water rendering feature which smooths out the shorelines which reduces water refraction in areas with shallow water.

There is a gradual blend from water to shore volumetric fog (for water) its per pixel screen space effects (post effects) are more complex.

Shadows are render-to-texture and are supersampled to make them look
softer.

Certain displacements use blended bumpmaps instead of a single bumpmaps (for example, displacements that blend between sand and rocks).

For our preliminary testing, we recorded custom demos on two maps, d1_canals_01a and d1_canals_09. We set all graphics options to their highest settings except for water reflection, which was set to world instead of reflect all. In determining which demos to go with we decided to go with sequences packed with action, we won’t drop any spoilers on you, but as you can see in the screenshots, we tried to record the most stressful demos possible at all times. We’re constantly evaluating which maps and sequences to record for demos, so if you have any suggestions for stressful areas you’ve noticed, please drop them in the news comments section for this article. Let’s get started…