Quake (TimeDemo1) is reported to run at the following speeds:
- 320x256 - 35-40fps
- 480x352 - 25-30fps
- 640x480 - 15+ fps
As for Descent/Descent 2, it's reported to run totally smoothly in 256 colours at 1024x768, and 32bpp at 800x600. With bilinear filtering and transparencies turned on, it runs at 15fps at 640x480. Higher resolutions and colour depths have been reported for all these, but don't as seem to be completely reliable yet.
RCI state that "these that these results are achieved without hardware acceleration, or any particular xscale optimisations". It is not known whether use will be made of the 3-D abilities of the nVidia graphics card - as the driver is closed source, there may be problems there, as this thread on TIB discusses.
Either way, it sounds like there's some nice upgrades for IYONIX owners coming up.
Source: RCI / comp.sys.acorn.games