You must license for a minimum of 16 cores per server, and a minimum of 8 cores per processor.
So, if a server has 2 x Processors and 4 x Cores per processor, you still have to license for a minimum of 16 Cores. If a Server has 4 x Processors and 4 x Cores per Processor, you must license for 32 Cores, because even though you have met the minimum of 16 cores per server (4 processors x 4 cores) you have not met the minimum order requirement of 8 x Cores per Processor.
PLEASE NOTE: Windows Server Core licenses come in packs of 2 when purchasing through OLP.
One Windows Server license goes on the physical server, and gives you the rights to run in two Virtual Machines. If you wish to run more VM’s, you can stack the licenses; to license for an additional 2 x VM’s you must license all the cores again on the physical server (like you would initially), making sure you meet the minimum criteria/ cover all Cores.
Windows Server DataCenter only starts to become cost effective if the customer wishes to run more than 10 x VM’s per server. The only difference between Standard and DataCenter is the virtualisation rights; DataCenter you get unlimited virtual machines whereas Standard you are only allowed two per server license.