If there's a store beyond a friend's friend's discarded server equipment that sells Opteron Barcelonas for 500kr I would like a link.. But I'm guessing you got a 'special deal' here.

According to boinc cpu test, ht seems to cost some performance.
He doesn't mean performance, he means price. You can't compare two CPUs to one CPU because the price difference between a UP platform vs. a DP platform, Nehalem or not, is massive.

Perhaps the diagrams should've counted both cores and threads so we'd avoid this bickering?