Windows Server Licenses Explained: The Grand Overview
Core Licenses, CALs, and Editions Explained — How to Find the Right Server License for Your Business.
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Short answer: Since version 2016, Windows Server is licensed per CPU core, with a minimum of 16 core licenses per server. The Standard Edition allows up to two virtual machines, while Datacenter allows an unlimited number. In addition, every accessing user or device requires a CAL (Client Access License).
Core Licensing: The Foundation
Since Windows Server 2016, cores, not processors, are counted. Microsoft mandates a minimum purchase: 8 core licenses per processor and at least 16 per server, regardless of how many cores the hardware actually has. A two-processor server with 6 cores each still requires 16 licenses because the minimum limit per server applies.
Standard vs. Datacenter
| Standard | Datacenter | |
|---|---|---|
| Virtual Machines | up to 2 | unlimited |
| Suitable for | physical or lightly virtualized servers | heavily virtualized environments |
For most small and medium-sized businesses, Standard is sufficient. Datacenter only pays off when many virtual machines are to run on the same hardware.
CALs: The Often Forgotten Second License
The server license alone is not enough. Every user or device that accesses the server also needs a CAL – either as a User CAL or Device CAL, depending on what is more cost-effective for your company. If one person uses multiple devices, the User CAL is usually the better choice; for shared workstations, the Device CAL is often preferred.
What about SQL Server?
SQL Server is a separate product with its own licensing, required in addition to Windows Server – as a database platform for business applications. SQL Server also requires appropriate CALs for accessing users, or it can be licensed per core.
“We had the server properly licensed – but simply forgot that every user also needs a CAL.” An IT manager describes how he only noticed this common pitfall during an inventory, before it became an expensive problem in an audit.
Conclusion
Used server licenses are a legal and cost-effective way to properly license your infrastructure. At Firstsoft, every license is individually checked before sale. See our entire server range, or directly Windows Server, SQL Server, and CALs.
