Can I just put new memory to the empty slots or should I rearrange the existing memory so that the biggest would be first or the faster first?At the first step you shoud add two 4GB modules, to have total of 6x2GB + 6x4GB.
Would it be better to replace the 1066 and buy 1333 now to extend to totaly 48 GB for an ESX envronment or is it not that important?It depends on processor model.3.