Windows Server Core Licensing: How many cores do you really need?
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Short answer: Microsoft requires a minimum of 8 core licenses per processor and a minimum of 16 per server - regardless of the actual core count. A server with a 6-core processor still needs 16 licenses, as does a two-processor server with 4 cores each. Count the physical cores of your hardware before purchasing.
The Basic Rule
Since Windows Server 2016, licensing is based on physical processor cores, sold in packs of 2. Two minimum thresholds apply simultaneously:
- a minimum of 8 core licenses per physical processor
- a minimum of 16 core licenses per server, even with only one processor
Three Calculation Examples
| Hardware | Actual Cores | Licenses Required |
|---|---|---|
| 1 Processor, 6 Cores | 6 | 16 (minimum per server) |
| 2 Processors, 4 Cores each | 8 | 16 (minimum per server) |
| 2 Processors, 10 Cores each | 20 | 20 (actual core count) |
Only when the actual core count exceeds 16 do you pay for what is actually installed - below that, you effectively pay for the minimum threshold.
"We specifically chose a processor with fewer but faster cores to save on licensing costs - only afterwards did we realize that the 16-core minimum completely negated that advantage for us." An IT buyer describes why he now includes licensing costs in his hardware selection, not just afterward.
Why this is important when buying hardware
Anyone planning a new server should factor in licensing costs. A processor with many cores may cost more upfront, but it doesn't automatically make the Windows Server license more expensive as long as you stay under 16 cores in total - our 16-core license already covers up to 16 cores.
What about virtual machines?
Core licensing refers to the physical hardware, not virtual machines. How many VMs you can run with it is governed by the edition: Standard allows up to two, Datacenter an unlimited number - regardless of the core count.
Conclusion
Count the physical cores of your hardware, not the number of processors. Our Windows Server 2022 Standard 16-Core License covers most small and medium server environments. For larger hardware or questions about the exact core count, our support team will be happy to help.
