Ïf you want to fold seriously, then cpu folding is the way to go. SMP units have a exponential bonus system for points (the faster you finish a work unit, the higher the bonus added to base points will be) and the gpu units don't. When i leave my i7 970 folding alone, it nets my around 42000 ppd. Adding a gpu drop the smp output to 35k. Adding a second gpu gets me 30-32k for the cpu and 15-17k per gpu. So yes you're right, the gpu ppd will compensate for the cpu loss. BUT, that is when folding regular SMP units. 4p systems using linux fold very special work units, called "bigadv". The bonus points on those are HUGE and as the gpu you install add points in a linear way, the bonus points will drop exponentially. So for this specific case, no it is not a good option. If you want to have yourself a monster folder, get a rack, multiple 4p g34 motherboard to fill it, MANY 12-cores magny-cours cpu (they are a little better at folding than interlagos), 4 stick of ram per cpu (try to get the best timings possible for ddr3-1333 ram) and a gold or platinum 600-700w psu. Install linux and follow one of the many good linux folding guide to optimise your rigs. You may want to pm buck nasty or bogmali, they have a lot of experience with folding and can give you good advice.