is ddr3 ram compatible with Model 1278?

Yes. Read https://discussions.apple.com/thread/2693275

Assuming that you have a 13" mid 2009 MBP, the correct RAM specifications are: 204-pin PC3-8500 (1066 MHz) DDR3 SO-DIMM.

That model can accept up yo 8 GB RAM and the best sources of Mac compatible RAM are OWC and Crucial.

Ciao.

If it is a mid 2010 13" MBP, the specifications for RAM are still the same but it will recognize 16 GB.

Message was edited by: OGELTHORPE