Quote - So i tried another scene which i had been messing around with and for the most part it was rendering ok (until i got about halfway through rendering then it dropped to 50% CPU usuage then decided to spaz out going between 1% & 50%)   It seems rather strange that the main scene im working on at the moment is causing poser to spaz out and not want to use the CPU

P7 and PPro work by dividing your scene into 4 quarters and then render each with it's own thread. This is fine if all 4 quarters of your scene are equally complex, but most scenes aren't like this, so what really happens is that 1-2 threads run through the easier quarters first and then sit around idle while the complex quarters chug on the remaining threads. In effect you get a quick 100% at the start and then end up with the performance of 1 or 2 cores and 25%-50% CPU load.

P8 though divides your scene per bucket so that all threads are always loaded to the max. AFAIK there is no way to do this on earlier versions.