There's been >2 hyperthreads in other server CPUs before. IBM and Sun/Oracle now or in the recent past have sold systems with 4-8 way threading. Of course, thes

There's been >2 hyperthreads in other server CPUs before. IBM and Sun/Oracle now or in the recent past have sold systems with 4-8 way threading. Of course, these would be niche systems even without lots of threads per core, so one's definition of a "common" workload would need to be adjusted accordingly. My experience was that they worked really well for big databases and Java app servers, less well for other uses.