Nº cpu's y procesadores

How many physical processors are there?
$ grep 'physical id' /proc/cpuinfo | sort | uniq | wc -l
2

How many virtual processors are there?
$ grep ^processor /proc/cpuinfo | wc -l
4

Are the processors dual-core (or multi-core)?
$ grep 'cpu cores' /proc/cpuinfo
cpu cores       : 2
cpu cores       : 2
cpu cores       : 2
cpu cores       : 2

"2" indicates the two physical processors are dual-core, resulting in 4 virtual processors.

If "1" was returned, the two physical processors are single-core. If the processors are single-core, and the number of virtual processors is greater than the number of physical processors, the CPUs are using hyper-threading. Hyper-threading is supported if ht is present in the CPU flags and you are using an SMP kernel.