Quote:
"Since you seem to be interested in everything related to 3Dfx I just wandered if you were aware of Primary Image and their 3Dfx based products. These were by far the most advanced application of 3Dfx technology at the time. The cards were aimed at the visual simulation market and not consumers. I used to work for them and wrote pretty much all the drivers and software for their 3Dfx based products.
They rolled out Piranha (
http://www.wave-report.com/1997_Wave_issues/wave723.html#723.12) in October 1997. This was a PCI board that had the following on it:
- an embedded Mips R5000 200MHz processor that ran an embedded version of Glide driven by the client side part of the Tempest scene manager, the srever sid ran on the PC. The client side did all the cull/draw calculations thus relieving the PC's CPU of this burdon and allowing multiple cards to be placed in a single PC (see below)
- a Voodoo 1 FBI with 3 TMU's (to my knowledge thie and the Baracuds are the only 3Dfx implementations by anyone to have 3 TMU's). This allowed for a tri-linear filtered base texture and a dithered trilinear filtered secondary texture, or even three dithered tri-linear textures in a single pass.
- A daughter card with another Voodoo 1 FBI with another 3 TMU's. This was used in SLI mode with the set on the base card.
The cards had a pixel bus connector system that allowed 2, 4 or 8 of them to be joined together and composited into a single channel to generate 2x, 4x or 8x rotated grid anti-aliasing. There were also tiling options so that half the cards could generate the left side of the screen and the other half the right side thus doubling the pixel fill rate and increasing the maximum resolution to 1280x1024. A second connector system was used to daisy chain the Pixel Clock, VSync and HSync signals, thus allowing mutliple channels to be video sychronized. Industrial PC's were used which had up to 20 PCI slots in a 19 inch 6U rack mount chassis. The PC was a single board computer (SBC) that plugged into the end slot. This sytem was developed almost 2 years before Quantum3D debuted their 3Dfx based AA offering.
In November 1998 Barracuda (
http://www.wave-report.com/1998_Wave_issues/wave906.html#anchor197511 and
http://www.primary-image.com/training_solutions/barracuda_design.htm) was released. This was similar to Piranha with the following updates - The Mips processor was upgraded to a 300MHz R7000. The Voodoo chips were upgraded to Voodoo 2, still 2 FBI and 6 TMU with the daughter card. An additional bus was added to optionally allow the geometry processing to be performed by a seperate card (called Cruncher) which had two 300MHz MIPS R7000's. The Cruncher would broadcast the polygon data to all the Barracuda's in a single channel by DMAing to a memory window. The local R7000 on each Barracuda would read the polygon data, add it's own local sub-pixel offset for anti-aliasing, then send the draw commands to the Voodoo 2 chips. A Galileo PCI bridge was added so that the 3Dfx graphics chips were visible on the PC's PCI bus (on Piranha the PC could not derectly access the Voodoo chips). Multi-card configuration options were the same as Piranha.
Primary Image had to stop using 3Dfx chips after Voodoo2 because 3Dfx signed there agreement with Quantum3D for them to be the sole source for later generations of 3Dfx based systems in the Visual Simulation field."
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