DDR3-1066, 1066Mhz, PC3-8500, CAS Latency 7, Non-ECC, Unbuffered, 1.5V, 204pin SO-DIMM.
Contains one (1) 4GB DRAM memory modules and is specifically designed and SPD configured for the MacBook Unibody Aluminum Model.
The Aluminum MacBook DDR3 Machine has a 6GB max out of the box, and can upgraded to 8GB when running Snow Leopard (106.6.6) or later, and the latest Apple Firmware..
To run 8GB in the MacBook Aluminum, find your Boot ROM Version by consulting your System Profiler. Instructions at http://support.apple.com/kb/HT1237.
The correct Boot ROM version for the MacBook 5,1 is MB51.007D.003 or newer. All other model IDs are unaffected. If you do not have this Boot ROM version, please download the latest MacBook EFI Firmware Update 1.4. You must also be running Snow Leopard (10.6.6) or newer to address 8GB on these computers.