Kyro uses region-based rendering which has several bandwidth friendly attributes: namely, on-chip depth-testing, early hidden surface removal and deferred texturing. An on-chip 32-bit mini- framebuffer results in superb 16-bit quality, efficient FSAA and multi-pass rendering. The tradeoffs are a tripling of geometry bandwidth, scene buffer storage on video board memory and labored texture filtering. The increase in geometry traffic is currently small compared to the depth-buffer and texture bandwidth savings. Kyro will better withstand the inevitable rise in texture layers than its contemporaries, on the proviso that scene geometry will not have increased in double-digit multiples.

Despite the afore-mentioned advantages, developer support for PowerVR has waned. There is a need to open up developer support and raise developer awareness. In addition, Kyro's performance headroom may be limited by architecture. The other challenge at hand would be to integrate hardware transformation and improve performance headroom.

Footnote: There were stability issues related to enabling AGP 4x on the test system. For Kyro, there were also unpredictable instances of frame skipping.

Kert Chian
Contributing Editor