If you do a google search for Spare parts Z600 you will find two motherboards available... the higher number one is the later version. If you search in the forum's search bar for Z600 boot block date you will find the specific date of the boot block for the original motherboard, and the later version one.
That is the best way to know exactly what you have. You always can consider swapping in the "revision 1" later motherboard which can run the later version processors.