Which exact processor model do the macbook pros have?
The processor used in the early 2011 15" and 17" i7 models is the 2.2 GHz quad-core (2720QM) Intel Core i7 Sandy Bridge with 6 MB on-chip L3 cache, so they have 4 cores and 8 threads.

Apple's MacBook Pro performance page makes it clear that Hyper-Threading is now standard on all MacBook Pro laptops.