I have some Mac memory and I was looking to buy some to match. The modules say MB982G/A-C on one sticker and MN982G/A-C/QP05. In looking I've found modules that just end after the G/A. Some that have the -C, some with the whole string. I've also found other that have a -AX. Are these all the same? Are they wildly different? They all seem to list PC3-8500 DDR3-1066 ECC DIMM, are there other differences.