Whatever your choice of computer system architecture NoMachine's Terminal Server, Enterprise Server, Terminal Server Node licensing is based on the number of cores per physical processors per system. NoMachine's pricing is not socket-based.
NoMachine treats multi-core processors as having multiple processors on one die. Therefore, a dual-core processor chip is essentially 2 processing CPU's on a single die. For NoMachine licensing purposes this is treated as a 2 CPU subscription license. In the instance of a quad-core processor, NoMachine would price this as 4 full processing CPU's since 4 distinct processors exist on one die. This would require a license for 4 CPU.
The following products are not licensed per core(s) on the server host: Workstation, Small Business Server, Enterprise Desktop.
Dual Core Processors
A Dual Core processor has two physical processors embedded in a single die sharing a single bus. Although the bus is shared, the CPU has in fact two physical processors. As such, a server having a single Dual-Core processor has two physical processors, and therefore requires one license for 1-2 CPU. When a server has two Dual Core processors (which yields four cores), a single license for 4 CPU is required.
Multi Core Processors
Current and future multi-core processers that have more than two cores (e.g. 4, 8, 16 and beyond) require a license that supports the total number of physical cores in the server. For example, a server with two quad core processors (equating to eight cores) will require an 8 CPU license.
With hyperthreading, a dual processor can have four logical processors that share the same execution resources of the dual processor core. In this scenario, when a server has a dual processor (four logical), one license for 2 CPU is required. When a server has 8 processor cores (which can function as 16 logical processors), a single license for 8 CPU is required.
Virtual Server Instances
For virtual server instances, NoMachine licenses are based on the number of actual allocated resources to the virtual machine. Thus on a 16-core physical machine which you want to partition to have two virtual instances, 8 CPU each, you will require, for example, one "NoMachine Terminal Server for Linux 8 CPU" per virtual server.