How to identify cpus, cores and hyperthreading

http://kbase.redhat.com/faq/docs/DOC-7715


Rules:

  • grep phy /proc/cpuinfo, how many different physical id will indicate how many physical cpu sockets.
  • If the siblings and cpu cores values match, the processors do not support hyperthreading (or hyperthreading is turned off in the BIOS).
  • It is worth noting that the presence of the "ht" flag in the cpuflags section of /proc/cpuinfo does not necessarily indicate that a system has hyperthreading capabilities