NEC Neon 250
The Neon 250 from NEC is a 3D graphics chip for AGP , which is based on IP of the PowerVR Series 2 and is therefore a tilebased deferred renderer (TBDR).
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Just six months after the PowerVR PCX2 , the PowerVR Series2, i.e. the next generation, was announced in early 1998 and should be launched on the market soon. There was a problem, however: At that time, Sega started working on their new console , the Dreamcast , and was looking for a graphics chip for this device. NEC / PowerVR prevailed against 3dfx and won the bid for the 3D chip with the NEC CLX2 . However, this required a lot of development time and of course had the highest priority over the almost identical PC graphics chip. When the Dreamcast appeared at the end of November, the next problem followed: its chip was utilizing NEC's production capabilities , so that it finally took until autumn 1999 before the PowerVR Series2 finally appeared as the Neon 250 for the PC market. Since the competition was of course not inactive until then, the Neon 250 was no longer competitive and very few cards were sold. Owners of the PowerVR Series 1 were even given a third discount on proof of purchase. If the chip is rated within the timeframe of its original announcement, both its speed and options such as antialiasing, texture compression (VQTC) and DVD acceleration (via motion compensation) were clearly ahead of its competition. In contrast to the PowerVR PCX1 & PCX2, the Neon 250 was a full-fledged graphics card with 2D and 3D functions.
Like all second-generation chips, this one also took on the task of projecting the polygons from the virtual 3D model onto the monitor. In addition, he now divided the image in the chip himself. This preliminary stage also created a list of all polygons belonging to an image tile and was given the logical name Tile-Acceleration. So one encountered an important point of criticism of the first series, which required a strong processor. The further processing remained the same: In the ISP (Image Synthesis Processor) the invisible polygons of a tile were sorted out and in the final TSP (Texture and Shading Processor) the textures were applied and illuminated. Both levels, however, worked much more compatible with Direct3D games than those of the Series 1 thanks to driver and / and hardware optimizations.
The only graphics card with this chip comes directly from VideoLogic .
His successor was the PowerVR 3-based Kyro , which was released a year later , and production switched from NEC to ST Microelectronics , which previously manufactured Nvidia Riva chips but could no longer deliver the TNT volume.
Model data
| Model | Neon 250 / PVR250 |
|---|---|
| year | 1999 |
| Code name | Highlander |
| Manufacturing process ( nm ) | 250 |
| Transistors in millions | 4th |
| interface | AGP or PCI |
| Max. Memory ( MB ) | 32 |
| Clock (Chip) (MHz) | 125 |
| Clock (memory) (MHz) | 125 |
| Pipes x TMUs x VPUs | 1x1x0 |
| Fill rate ( MT / s) | 125 |
| Memory bandwidth ( GB / s) | 1 |
| Memory bus type | SD DRAM |
| Memory bus width ( bit ) | 64 |
| DirectX version | 6th |
| OpenGL version | - ( MiniGL wrapper ) |
| Features |
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