3Dlabs Oxygen GVX1 PCI

Two parts to this Equation

The Oxygen GVX1 can be considered to be a step above the Oxygen VX1 (which closely resembles the Permedia 3 Create! that we reviewed a while back), with a major difference being that the board itself features not only the GLINT R3 Rasterization Processor but also an on-board GLINT Gamma G1 Geometry Processor.

The base of the GVX1 can be considered to be the GLINT R3 rasterization processor that is actually the same Rasterization unit used on the Oxygen VX1. The GLINT R3 is fully OpenGL 1.2 compliant in silicon and thus offers full compatibility with newer OpenGL 1.2 applications as well as older 1.1 applications. Because the GVX1 is a professional level graphics accelerator, it isn't surprising to see support for 2048 x 2048 textures and 32-bit color/Z-buffer support implemented in the GLINT R3 rasterizer.

The R3's 230Mtexels/sec bilinear fill rate is indicative of a 115MHz core clock speed of the R3. The trilinear fill rate of the R3 is at half of the above number at 115Mpixels/sec. Both of these theoretical values put the fill rate performance of the GVX1 around the level of NVIDIA's TNT2 from the gaming world.

The R3 provides the GVX1 with the 300MHz RAMDAC that it requires to drive its high quality 2D and 3D graphics output as well as the 128-bit memory interface of the card.

On the other end of the 128-bit memory bus are the 16 - 2MB Samsung SDRAM chips that make up the 32MB frame buffer. The Samsung chips are rated at 8ns, making the default memory clock of the GVX1 no greater than 125MHz. This puts the amount of memory bandwidth available to the GVX1 at approximately 2GB/s, which is lower than what we are normally used to with gaming cards.

Keep in mind that the focus of a professional graphics board is much different than the focus of a gaming board, thus the available memory bandwidth carries a different weight in factoring performance. Most current games rely on taking a few relatively simple scenes, constructed of in upwards of 10,000 - 20,000 polygons and applying multiple textures to them. Because of this, a high polygon throughput is not the most important factor to accelerating today's games. Instead, having a high fill rate is almost directly proportional to performance in today's games. While this will change in the future with polygon counts increasing, for now, as 3dfx has been preaching in the past, fill rate is king.

The professional 3D arena is almost the complete opposite. The applications being used in this environment are intended to create complex structures and objects, modify them in real time and require the utmost attention to the quality of the picture on the screen. While a high fill rate is desired, especially when dealing with manipulating and rendering textured objects, more important to professional 3D applications is having a high polygon throughput. This is where the second part of the GVX1's equation comes into play -- the Gamma G1 Geometry Processor.