Glad you asked ;-) It's called Hyper-threading [1] and works best when the scheduler is aware. Provided in some Intel's CPUs (2 threads per core) and in Sun's (

Glad you asked ;-) It's called Hyper-threading [1] and works best when the scheduler is aware. Provided in some Intel's CPUs (2 threads per core) and in Sun's (later Oracle's) UltraSPARC T1...T5 (8 threads per core). [1] http://en.wikipedia.org/wiki/Hyper-threading http://en.wikipedia.org/wiki/Hyper-threading [2] for example, CONFIG_SCHED_SMT in linux