you want VOLUMIC explosions on a DESKTOP machine.
volumes and machines under the dual athlon/dual Xeon spec just dont mix i'm afraid.
If you want realistic volumetric fire effects you're looking at 8 hours+ a frame plus the time it take to set up a particle system to do what you want it to.
Volumes are a nice idea but they take way too long in practise to render for production schedules. Nice as a study in how to waste processor cycles though.
What i'd suggest you do is find some explosion animations and opacity-map them onto a primitive...and just have them play when you need to.
Failing that...just put an explosion in as a glow effect on some particles (i think lightwaves' renderer can motion blur glow effects) with one volume light in the middle. That could give a nice effect.
just whatever you do - DONT TRY VOLUMETRIC EXPLOSIONS.
they take forever
they look crap
they're hard to setup.
