I saw a review where the reviewer had an FX (retail) that had 24M of cache rather than 16M. Could another 8M of L3 be those missing transistors? I wouldn't know so just asking the question.

Could it also be that the server variants have the full compliment of cache as the speeds are slower so fit the TDP but the retail parts cannot fit inside the TDP with all that cache so some of it has been disabled?

The transistors might still be there but just not used in retail parts.

The marketing dept have then failed to make the rationalisation between server transistor count (used) and retail transistor count (used) which then compounded the 'so many transistors for so little performance' argument? If so, no wonder they got culled.

Just some musings from me here.