Memory bandwidth is becoming a very important factor in 3D accelerators quickly as we transition into high resolutions and high color depths. The more complex we make 3D games or graphic applications, the more memory bandwidth we need. Now, depending on the architecture of the chip, we may need more for one card than we will for another. For example, the GeForce based boards need a great amount of bandwidth to push such insane fill-rates with high resolution, high color, T&L and various filtering modes. This is why we're seeing DDR based graphics boards pop up to help alleviate this problem for the GeForce. In the future, 3dfx and ATI are going to take yet another route where "brute force" is used by allocated a set amount of memory per graphics chip and diving work between the two. This allows for theoretically double the memory bandwidth. S3 is using SDR for the Viper II that is clocked at 155 MHz giving them a 2.5GBs/sec memory bandwidth. With the use of texture compression and efficient driver tweaks, S3 must not feel the need for greater memory bandwidth solutions just yet.
S3 Texture Compression
S3 texture compression (or S3TC) has been around since the birth of the Savage 3D and has been trying to get its foot in the door with software developers since. Although the feature hasn't received as much support as S3 wants, it seems that developers are beginning to slowly move over. We're seeing game developers like Epic (Unreal), id (Quake 3 Arena), Monolith (Shogo2) and Raven (Soldier of Fortune) providing support for S3TC in their upcoming titles. S3 not only offers higher visual quality with their texture compression but also accelerate performance for large texture scenes. These instances maybe be few right now but with 3dfx other big graphics players pushing texture compression, you sure can bet texture compression will become a standard feature.
With ATI standing alone in the consumer high performance video arena, only S3 is beginning to offer some type of real challenge. The Viper II now features enhanced DVD features that improve visual quality. Motion compensation and 16-tap upscaling and downscaling greatly improve the visual quality of software DVD playback. While not offering the best DVD performance, the Viper II offers a very good runner-up when it comes to DVD playback. The software DVD playback on our P!!! 550 test system was smooth and visual quality differences between ATI and S3 were very difficult to tell.