Here's another dual CPU system. I meant to build this initially instead of the system above, but ended up with a 2011 v3 motherboard and ended up keeping it and building out the system in the message above and this one.
Anyways, this is a dual Xeon E5-2670. The difference between Schmuckley's single thread number and this one is interesting as my number is significantly lower. I think part of that is due to this system running Windows server 2016 preview 5. I noticed that the overall score for Passmark was noticeably lower when in Server 2016 v. Windows 10. I am currently trying out server 2016 because the Super Micro dual 2011 motherboard I am using runs Windows 10 ok until you try to do a restart, then it hangs in the restart process. Apparently some other 2011 boards had the same issue and it was fixed with a BIOS update. Unfortunately, the last BIOS for my board is dated 2013.
There is also the Non Uniform Memory Access issue with dual CPU MBs. Each CPU its own memory, which is shared between the CPUs, but accessing the other CPU's memory is not as fast. Despite the single thread number being low, the multi thread number still was pretty good.