Solid Impact was a graphics card developed by Silicon Graphics for their Indigo2 line of workstations. As the name implies, it was intended for solid model graphics, that is, graphics that lack textures. It was possible for a Solid Impact card to display textured graphics, but all texture mapping had to be done in software.
It was more than twice as fast as the Extreme Graphics system it replaced, while simultaneously running cooler and using only one slot (vice three). Two higher-end versions existed - High Impact, which included hardware texture mapping, and Maximum Impact, which had texture mapping and a second geometry processor, allowing it to handle much larger scenes.
Versions of the Impact series of cards were also produced for the SGI Octane series. Solid Impact's Octane equivalent was called, unsurprisingly, SI. Its more featureful kin were SI+T (equivalent to High Impact), MXI (Maximum Impact), and SSI (Super Solid Impact, basically an MXI without any texture memory).