Voodoo3

Voodoo3 was a series of computer gaming video cards manufactured and designed by 3dfx Interactive. It was the successor to the company's high-end Voodoo2 line and was based heavily upon the older Voodoo Banshee product. Voodoo3 was announced at COMDEX '98 and arrived on store shelves in 1999. The Voodoo3 line was the first product manufactured by the combined STB Systems and 3dfx.

The 'Avenger' graphics core was originally conceived immediately after Banshee. Due to mis-management by 3dfx, this caused the next-generation 'Rampage' project to suffer delays which would prove to be fatal to the entire company.

Avenger was pushed to the forefront as it offered a quicker time to market than the already delayed Rampage. Avenger was no more than the Banshee core with a second texture mapping unit (TMU) added - the same TMU which Banshee lost compared to Voodoo2. Avenger was thus merely a Voodoo2 with an integrated 128-bit 2D video accelerator and twice the clock speed.

Much was made of Voodoo3 (christened 'Avenger') and its 16-bit color rendering limitation. This was in fact quite complex, as Voodoo3 operated to full 32-bit precision (8 bits per channel, 16.7M colours) in its texture mappers and pixel pipeline as opposed to previous products from 3dfx and other vendors, which had only worked in 16-bit precision.

To save framebuffer space, the Voodoo3's rendering output was dithered to 16 bit. This offered better quality than running in pure 16-bit mode. However, a controversy arose over what happened next.

The Voodoo3's RAMDAC, which took the rendered frame from the framebuffer and generated the display image, performed a 2x2 box or 4x1 line filter on the dithered image to almost reconstruct the original 24-bit color render. 3dfx claimed this to be '22-bit' equivalent quality. As such, Voodoo3's framebuffer was not representative of the final output, and therefore, screenshots did not accurately portray Voodoo3's display quality which was actually much closer to the 24-bit outputs of NVIDIA's RIVA TNT2 and ATI's Rage 128.

The internal organisation of Avenger was not complex. Pre-setup notably featured a guardband clipper (eventually part of hardware transformation and lighting) but the pixel pipeline was a conventional single-issue, dual-texture design almost identical to that featured on Voodoo2, but capable of working on 32-bit image data as opposed to Voodoo2's pure 16-bit output. Avenger's other remarkable features included the 128-bit GDI accelerator debuted in Banshee. This 2D engine led the Voodoo3 to be considered one of the more high-performance video cards of its generation.

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