Sega boosts VideoLogic with choice of PowerVR

Sega boosts VideoLogic with choice of PowerVRRichard Wilson Sega’s decision to choose the 3Dgraphics accelerator from the VideoLogic/NECpartnership for its next games console vindicates VideoLogic’s decision to revamp its PowerVR graphics accelerator (see EW, May 27). First launched back in 1996, the important design features of PowerVR were reduced on-chip 3D rendering processing with part of the frame by frame image rendering process carried out by the host CPU. It made use of standard synchronous DRAM for off-chip frame buffer and texture memories, less expensive than specialised graphics RAM. Roaring back… Redesigned PowerVR plays for Sega. The aim was to reduce system complexity and cost, without losing performance. The redesigned PowerVR chip reverses the first of those features while adding more on-chip performance and new features such as support for 2D graphics. Also new with the latest version of PowerVR is full compatibility with Microsoft’s DirectX6 graphics operating system and the Direct3Dapplication programming interface (API). Any 3D graphics chipset is only as good as the games software that will run with best performance on it. VideoLogic’s work with Microsoft over the API should prove vital for any future success of PowerVR. In terms of raw numbers, the sustained maximum graphics performance on a Pentium II 333MHz PC is 1.2 million forward facing polygons/s, according to VideoLogic. The theoretical maximum lifts to 4 million polygons/s when Intel’s next generation Katmai and Merced processors are brought into the picture. But it will be 1999 before that can be put to the test. Similarly, the appearance of Katmai and Merced, and a lot more graphics memory, should mean that game-players should be able to view top- selling game Quake II at a resolution of 1600 x 1200. What has changed in PowerVR is that the processing power of the second generation chip is twice that of its predecessor. The earlier version differed from many of its competitor devices in that it required the system’s host CPU to implement some of the 3D image rendering. Customers seem to have told VideoLogic that this was not such a good idea as it tied up CPU time which could be used for other things, like whizzy games software. The company also says that image quality will be improved with jagged-edges smoothed by a technique known as full scene anti-aliasing. However, this will be hard to assess until games supporting full scene anti-aliasing appear on the market.
What does this mean when you run a game like Quake II today? According to VideoLogic, at a resolution of 640×480 and on a Pentium II 266MHz, the results were not too far off those from a single Voodoo2 accelerator from rival supplier 3Dfx, incidentally the accelerator supplier previously used by Sega.

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