Windows Server® (WS) 2012 will be available in two general purpose editions: Standard and Datacenter. These editions will have the same technical capabilities and be licensed by the same paired-processor model. The only differences between the editions will be virtualization use rights and license price. Even with the elimination of the Enterprise edition, many organizations may have slightly lower licensing costs. Client Access Licenses (CALs) and reassignment rights remain largely unchanged, and the addition of even one WS 2012 server in an organization could trigger the need for new CALs throughout the organization.

Edition Simplification

In the past, technical features were a key differentiator between server editions. For example, WS 2008 R2 Standard edition could only use up to 32GB of RAM and up to four processors. WS 2008 R2 Datacenter could use up to 2TB of RAM and 64 processors. WS 2008 R2 Standard edition did not include the Windows Server cluster feature for failing over applications and services across servers.

WS 2012 Standard and Datacenter editions each allow an organization to utilize all Windows Server features. The main difference in the editions concerns use rights for virtualization (explained below).

Three Editions Eliminated

WS 2012 will not offer the following editions, which were present in WS 2008 R2:

  • Enterprise is replaced by WS 2012 Standard. Enterprise was targeted at servers dedicated to a single heavy-duty workload, such as a database management system, or servers hosting a light virtualization workload—four or fewer virtual machines (VMs). Customers will be able to license additional servers to run WS 2008 R2 Enterprise by purchasing WS 2012 Standard and exercising downgrade rights.
  • Windows Web Server is replaced by WS 2012 Standard. Web Server was targeted at servers dedicated to a single-purpose Internet-facing Web site, Web application, or Web service. Because Web Server did not require CALs when used in this manner, WS 2012 Standard will not require CALs when used for Web workloads. Windows Azure will also offer several options for Microsoft hosting of Windows Server—based Web sites.
  • Windows HPC Server has been eliminated as a separate edition. Windows HPC Server was targeted at high-performance computing (HPC) applications that use multiple processors or computers working in parallel for compute-intensive calculations. Instead, Microsoft has indicated that an "HPC pack" will be available in the future as a free download for WS 2012 customers, and this pack will likely provide the head node services of Windows HPC Server and run on WS 2012 Standard or Datacenter edition. As with Web Server, Windows Azure is also playing an expanded HPC role.

Licensing Model Changes

As with previous versions of Windows Server, licensing WS 2012 Standard and Datacenter editions still generally requires licenses for servers as well as for the client users or devices that access servers. But how editions are licensed for each server is changing.

Server Licenses Cover Two Physical Processors

Each WS 2012 Standard and Datacenter server license covers two physical processors. For example, a server with four processors must have two WS 2012 Standard or Datacenter edition licenses. The number of processor cores in a physical processor has no impact on licensing rules or costs, in contrast to the rules for the recently released SQL Server 2012. This is a change from WS 2008 R2, where a single Standard edition license covers a server with up to four processors, an Enterprise edition license covers up to eight processors (in both cases reflecting technical limits of the product), and a WS 2008 R2 Datacenter license covers a single processor only. Microsoft indicates that most of the installed base of WS 2008 R2 servers has one or two processors.

Regardless which edition is chosen, an organization must buy sufficient licenses to cover all processors in a server—no processor can be left in an unlicensed state. Licenses are sold in pairs, and a license pair cannot be split across physical servers.

The new WS 2012 licensing model is consistent with the licensing model for System Center 2012, Microsoft's management tools for managing Windows servers and server applications, and the latest model for the Enrollment for Core Infrastructure (ECI). The ECI is an Enterprise Agreement enrollment that licenses servers for the Windows Server OS with management by System Center products.

Virtualization Usage Rights Change for Standard

WS 2012 Standard includes the right to run up to two VMs per license. This is a change from WS 2008 R2 Standard, which only allowed running a single VM. (The discontinued Enterprise edition allowed up to four VMs). WS 2012 Standard licenses may be stacked to accommodate more VMs. For example, if a server has two processors and the organization wants to run eight VMs simultaneously on this server, the organization may assign the server four WS Standard 2012 licenses.

As with WS 2008 R2, WS 2012 Datacenter includes unlimited virtualization rights, meaning a server licensed for Datacenter may run as many VMs as the hardware can support.

Downgrade Rights

Many organizations purchase a license for a current version of Windows Server and then exercise downgrade rights to deploy a previous version, typically because a critical application is not yet supported on the current version. Not only does Windows Server offer version downgrade rights but it also includes "down-edition" rights as well. (Not all Microsoft products offer down-edition rights.) Customers who purchase WS 2012 Datacenter may downgrade to any previous version of Datacenter, Enterprise, or Standard edition. For example, an organization may license a server for WS 2012 Datacenter but run WS 2012 Standard in VMs.

Customers who purchase WS 2012 Standard may downgrade to any previous version of Enterprise or Standard. This ability to use older versions of Enterprise will be useful for organizations that need to continue to expand their existing WS 2008 R2 Enterprise deployments.

Some Licensing Rules Unchanged

As previously stated, the rules regarding CALs remain mostly unchanged:

  • CALs are still required for employees or their devices accessing Windows Server, and External Connectors are still an option (instead of CALs) for licensing access by external users, which Microsoft defines as users who are not either your or your affiliates' employees, or your or your affiliates' onsite contractors or onsite agents
  • Windows Server CALs can be bought for either users or devices (same price but different part numbers)
  • Use of Remote Desktop Services (RDS) and Rights Management Services (RMS) requires additive CALs; that is, the right to use those features is not included in the Windows Server CAL.

The trickiest aspect of the CAL requirement has to do with when the new CALs come into play. As was the case with WS 2008, deployment of the first server with WS 2012 in the organization could obligate the organization to roll out new CALs organization-wide, because any employee or employee device that accesses the server will require a CAL for WS 2012. (In contrast, deploying WS 2008 R2 in place of WS 2008 did not require new CALs because in the past Microsoft has not issued new CALs for R2 versions of Windows Server.) Microsoft says this should not be an issue for many organizations because it is common to have SA on Windows Server CALs (typically by purchasing and maintaining SA on the Core or Enterprise CAL Suite, both of which include the Windows Server CAL).

License Reassignment Unchanged

The rules for reassigning licenses are unchanged. Windows Server licenses purchased through Volume Licensing may not be reassigned from one server to another within 90 days of the last assignment, except in the event of permanent server hardware failure. The attachment of SA to the server license does not change the reassignment count-down clock.

Although SA includes license mobility that allows customers to move Microsoft server-based applications into off-premises hosted data centers, it is important to keep in mind that customers cannot reassign a Windows Server license to a hoster's server that's being used in a multitenant scenario. Instead, use of Windows Server on hosters' servers must be licensed by the Service Provider under existing Services Provider License Agreement (SPLA) rules.