I have written a fairly redimentary Particle Demo, and it runs fine on most computers, except from some mates who have Radeon Sapphire 9700 Atlantis pro cards.
The demo will run fine on both computers if they install their previous video cards, but it chugs ridiculously when they have their ATI cards installed.
They both run Win2k and are running the latest drivers.
The particle demo just consists of textured quads, but the chug doesn’t appear to have anything to do with the number of quads being displayed.
Any ideas?