Take a look at this ;
Bottom left= realtime Lightwave preview, running at less than 1 fps(hardly enough to work with),
Top right= Lightwave render ,pld 3 pass(rendertime=10.0 sec),
Top left= realtime PIMTools preview running at 40 fps with 4X AA / 8X Anisotropic Filtering!
AMD 64 bit Athlon 3000+
512 Mb ram
ATI Radeon 9700 mobile