EdVassie (4/9/2014)
Our discussions with Microsoft and its license resellers have shown that the following is accepted:If you set processor affinity to match the number of cores you have licensed, then you can validly license fewer cores than are available to Windows. This applies to both physical and virtual instances of Windows.
The licensing must cover all cores that you are using. If you have a 32-core box and you use affinity to set 8 cores for IO usage and a different 8 for CPU workload that is 16 cores you must have a license for.
I've spoken to a few people who have had similar conversations with resellers and still found themselves coming unstuck when they got audited.
Unless something's changed since we last looked at this, setting processor affinity is not valid. For one, that only affects the core database engine, not other elements (like SSIS, SSAS for example) and I think even CLR and service broker. There's nothing on paper from Microsoft declaring these settings have any impact on licensing.