My mac took a **** and I was thinking of putting in a new CPU as someone suggest I try. But I was wondering if I could put in a high cpu than the one I have in right now, and could I add more ram? Is there any way I have to go about adding them, in incremants? Like if I add a 1.2ghz processor can I only add ram that between certain capacities? I have an 867mhz processor (not sure about exact number) and 512mb RAM.