"The requirement for GF1/Radeon 7500 as an absolute minimum is fundamental to the way the technology works, and was non-negotiable for the advances that I wanted to make. At the very beginning of development, I worked a bit on elaborate schemes to try and get some level of compatibility with Voodoo / TNT / Rage128 class hardware, but it would have looked like crap, and I decided it wasn't worth it.

The comfortable minimum performance level on this class of hardware is determined by what the artists and level designers produce. It would be possible to carefully craft a DOOM engine game that ran at good speed on an original SDR GF1, but it would cramp the artistic freedom of the designers a lot as they worried more about performance than aesthetics and gameplay.

Our "full impact" platform from the beginning has been targeted at GF3/Xbox level hardware. Slower hardware can disable features, and faster hardware gets higher frame rates and rendering quality. Even at this target, designers need to be more cognizant of performance than they were with Q3, and we expect some licensee to take an even more aggressive performance stance for games shipping in following years."