The Competition: Kyro II From ST Microelectronics
Guillemot/Hercules is the first manufacturer to offer a graphics board based on the Kyro II . As you may know, this little chip is definitely able to play in the league of NVIDIA's GeForce2 MX and ATI's Radeon SDR. As the Kyro II does not offer either AGP 4x or wide memory bandwidths (5.5 ns SDR SDRAM at 180 MHz), the benchmark results are quite diversified. However, in most benchmarks the Kyro II is able to beat both the GeForce2 MX and ATI's Radeon DDR board. Depending on the resolution and colour depth, Kyro II may even be able to beat the GeForce2 GTS.
ST Microelectronics played it smart as they did not even try to boost memory bandwidth by using fast and expensive memory chips. Instead they decided to avoid unnecessary data movements and pixel fills using TBR technology (Tile Based Rendering), this being the main technology selling point for the Kyro II technology.
Typical 3D scenes are populated with an array of 3D objects. TBR simply checks which objects are visible to the spectator and only fills the required polygons. ATI's HyperZ goes a similar way. In contrast, the NVIDIA engine always fills everything and then sorts out the visible polygons using Z-buffering - resulting in a big burden on memory bandwidth. The impact on memory bandwidth is tremendous when there is a lot going on in a scene, which is the case with most 3D shooters and action games. NVIDIA has opted for brute force to overcome this problem; TBR finesses an alltogether different approach to bypass potential bottlenecks.
