FX5900 - Windowed 3d Apps

I've read that these cards run at lower frequencies when in 2d mode, and
then increase speed for 3d games.
However, I wonder how they handle a windowed 3d app like Lightwave, or 3d
Studio, etc? Do they run at 2d speed, or 3d speed? And if you are switching
back and forth from Lightwave, to say, Photoshop, is it constantly changing
speeds (along with the fans).

Thanks so much

if they do run at the slower speed in apps you could overclock it to run at
the full speed all the time if your cooling is upto it.