More Memory will allow for larger file manuevering, for example higher res materials, less bogging down when you have alot going in one scene. Stronger(more Mem)Video card will help the memory. There are also tricks like Saving the file more frequently. Better Processor will decrease render time. Reads and processes information faster. You lost me on the PS, do you mean allocating system resources?

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Ockham's razor- It's that simple