G80: NVIDIA GeForce 8800 GTX

Half-Life 2: Episode One

Publisher: Valve Software

Half-Life 2: Episode One is the first in a series of episodes that extends the Half-Life 2 story far beyond where the original left off. Valve has implemented its HDR rendering and used it to great effect in Half-Life 2: Episode One. There are also new higher-resolution textures, new facial animations and some AI improvements made in the new game too.

Anti-aliasing and anisotropic filtering were controlled from inside the game, and thus the drivers were left set to "Application Controlled". There are three options for the method of HDR used in this title. You can either disable HDR completely, make use of "Bloom" which is just what it says and less resource hungry in comparison to "Full" which, again is just what it says. It utilises a full dynamic range with the iris effect too.

We did a five minute manual run through from the Exit 17 level. It involves lots of HDR, lots of explosions and both indoor and outdoor scenes. The section we have used is typical of some of the more stressful areas in the game. Thankfully though, the game runs superbly on a wide range of hardware, while still looking absolutely stunning.

24" widescreen gaming:

The Source Engine isn't the most taxing these days, although it is still one of the best looking - a testament to the effort put into its programming by the team at Valve. When playing on a 24" display, each of the three cards here turns in a good result, with the GeForce 7950 GX2 proving the least capable, although only insofar as it lags behind on AA quality. The image quality of the 8xQ with transparency super-sampling AA on the GeForce 8800 GTX is not to be underestimated - the anti-aliasing quality is superb.

One thing we did notice during our testing though was that the image quality on GeForce 8800 GTX was different to the other cards. We spoke to NVIDIA about the quality differences we were seeing and we were told that GeForce 8800 GTX renders very close to the reference rasteriser, providing us with screen shots to prove the statement too.

30" widescreen gaming:

If we put the image quality differences aside, Half-Life 2: Episode One was the game that showed the smallest performance difference we've seen at 2560x1600 between the GeForce 8800 GTX and the previous high-end offerings from both ATI and NVIDIA. We put this down to the incredible scalability of the Source engine.

All three cards were able to maintain a degree of AA along with the maximum in-game detail settings. Having said that though, the GeForce 8800 GTX was by far the best performer, managing to achieve smooth gameplay with 8x transparency super-sampled anti-aliasing enabled, while both GeForce 7950 GX2 and Radeon X1950 XTX were only capable of 2xAA.