To do the actual additions and make the other necessary "decisions". The CPU is also know as the processor.
by volatile do yo mean which looses its content when powered off? If so, yes most of them. I've a seen they also sell wood/stone CPU, which are CPUs that are not powered at all.They can retain there...
The Top CPU right now is the Intel Core i7-980x Extreme Edition
Berkeley RISC, one of two seminal research projects into RISC-based microprocessor design taking place under ARPA's VLSI project