Dual Opteron 6140 vs 6376 Cinebench R20 + Booting up

The Opteron 6140 has 8 Cores/Threads compared to the 6378 which has 16 "Cores"/Threads (8 Modules each with 2 threads). AMD marketed the Opteron 62xx and 63xx as having Cores but the design didn&really offer cores as some resources were shared. As we see in this video the Opteron 6378 doesn&have twice the performance even though it has double the thread count of the 6140. The motherboard used is the Supermicro H8DGi(6)(-F). The base frequency of the Opteron 6378 is lower than the 6140 but the all core boost is the same frequency as the 6140 (which doesn&have boost).