Important clarification to add Processor vs Core Microsoft definitions Page shall contain the exact definition of what a processor is microsoftly speaking Indeed this concept is quite blur if we refer to the numerous pages from different Microsoft web sites For instance at we can find Windows 2003 Server Standard x64 R2 64 bits 4 way symmetric multiprocessing SMP support Other example for the same Windows Server 2003 R2 Standard x64 Edition at memory bound applications that do not require more than four processors supports up to 32 GB of RAM on 1 to 4 way servers Windows Server 2003 R2 Standard x64 Edition supports up to four CPUs on one server If we refer to Wikipedia multiprocessor architecture or multicore processor are both SMP architecture Thus by speaking sometimes about 4 processors support sometimes about 4 way SMP support Microsoft confuses us all Coming to a Quadri 4 cores based server 16 SMP this leads to go from a Standard edition 4 processors support to a DataCenter edition 4x4 16 SMP support thus raising the license price as for no less than 700