Based on everything we know, we can only conclude that the CS: Source video stress test is essentially a Half-Life 2 benchmark that's available to the public right now. Naturally, that piques our curiosity, especially since last time around, the ATI cards were absolutely trouncing the NVIDIA cards in HL2 benchmarks. There was only one thing to do: we rounded up thirteen different DirectX 9-class video cards for a Source engine benchmarking bonanza.
Has ATI maintained its monstrous lead in Half-Life 2 performance over NVIDIA, or have the events of the past year allowed NVIDIA to catch up? Read on to find out.
The Source engine video stress test
The Source engine video stress test included with the CS: Source beta isn't a real in-game benchmark. It doesn't use a real Half-Life 2 level, doesn't test game physics, and doesn't play sounds back. It is, however, a pretty darned good video card benchmark, because it incorporates a whole range of pixel shader effects, sometimes layering them on top of each other, to produce lots of eye candy. The video stress test is alsolo and beholdvery much a stress test; it seems to throw a series of worst-case scenarios at the graphics card to see how it fares. In other words, if a graphics card can make it through the video stress test without choking, I'd expect it to hold up its end of the bargain in Half-Life 2, as well.
To give you some idea what the stress test does, let's have a look at a few screenshots. The first one is from the opening stage of the stress test, where multiple translucency effects are layered on top of one another. Note, also, the reflective and refractive water below. This scene is packed with DX9 pixel shader effects.
Next up is a room illuminated by a fire effect. On the pedestal in the middle of the room, you can kind of see a translucent player character, though it is tough to pick out in this shot. Also note the walls, which are covered with very detailed bump or normal maps. The low resolution of this screen shot doesn't do it justice; the textures still look exquisitely detailed at 1600x1200.
Finally, we have a room with a series of virtual TV sets, displaying images from the previous test room on them through the magic of portal rendering (or, uhm, render to texture). Again, the floor is covered with water, and settled above the water is a thick, blue volumetric fog.
All of these scenes rendered perfectly on all of the video cards we tested, with a couple of minor exceptions that I'll describe shortly. Overall, the Source engine's visuals are much higher quality than current games and don't seem to vary widely from card to card, much like we've seen in DOOM 3. We have refrained from providing extensive screenshot comparisons between cards because of some limitations in the CS: Source beta, but to the naked eye, there's little difference between ATI and NVIDIA in terms of image quality. Let's talk about the differences we were able to spot...