The problem with formatting in real time is that it takes a chunk of CPU time just to frantically store raw data, never mind resizing and encoding or some such. Hence the 100% or 50% options. Unless you have a rig that can play WoW twice over (in which case, PLAY A BETTER GAME ), you should just record in full-size, then slap it through a DivX or Xvid encoder. Doesn't take too long.