This Article will describe the new licensing requirements for Microsoft SQL Server 2012. Before we begin, here's a bit history on SQL Server 2008:

SQL Server 2008 R2 offered multiple editions (Datacenter, Enterprise, Standard, Workgroup and Web) with both Per Processor and Per User licensing. In this model, Datacenter edition was the only license option that provided unlimited instances within a virtualized environment. SQL Server 2012 has made a number of changes to this model. First, Datacenter and Workgroup editions have been removed. Enterprise edition is now the version that provides for unlimited virtualization. Secondly, all Per User license versions for these editions have been removed. A new Per User license, BI Server, has been added for customers who need Enterprise functionality without Enterprise pricing. Most importantly, however, is that Microsoft has moved from a Per Processor licensing model to a Per Core licensing model.

Per Core Licensing for SQL Server 2012
SQL Server 2012 Enterprise, Standard and Web editions are now all licensed by core instead of processor. Specifically, you will need one license for every 2 cores (minimum 2 licenses per processor) in your dedicated server. You MUST license all cores, regardless of what the software will actually use.

Use of Microsoft SQL Server 2012 in Private Cloud gives you additional options. You always have the option of using host-based licensing of Enterprise edition to leverage the unlimited virtualization use rights. If you prefer to use VM-based licensing, the math gets a little bit more complicated. You must first determine how many processor cores are being used by your vCPUs. In many cases there is a 1:1 ratio between vCPUs and cores. If this is not the case, multiply your vCPU count by the number of cores per vCPU.

• If you allow for 4 vCPUs to use a single core and your VM uses 2 vCPUs your VM uses .5 cores.
• If you allow each vCPU to use a two cores and your VM uses 2 vCPUs your VM uses 4 cores.

Once you know how many cores your VM uses, divide that number by 2 to determine how many licenses you require.

For additional resources and information about SQL Server 2012, visit the Microsoft SQL Server Pricing and Licensing Overview or refer to this Microsoft's Datasheet and FAQ for more details.