Venice = newer core with better memory controller, 90nm part
Clawhammer = older core, 130nm (meaning higher power consumption)
The diff in the two Venices is here:
#16: ADA3500BWBOX
#17: ADA3500BPBOX
"BW" is the E6 core, newer revision fixing minor errate. "BP" is the E3 core, which supposedly OCs better than E6. I purchased an E3 OEM 3200+ from Ewiz and it had trouble hitting 2.5GHz, which may have been due to the board.