Hi @macdaddysolutions,
Thanks for the information particularly RE:
macdaddysolutions wrote:
One 8GB chip WILL NOT WORK...
Your Mid 2009 Macbook Pro can run PC3-8500, PC3-10600, PC3-12800 (1066mhz, 1333mhz, 1600mhz) literally anything above 8500 in the PC3 format will work...
THE ONLY THING THAT IS ABSOLUTELY A MUST IS THE VOLTAGE!!!! Most newer chips run on 1.2v All Macs 2010 and below run on 1.5v so you'd need to find 1.5v higher speed RAM.
Also RE:
macdaddysolutions wrote:
Memory is designed to be backward-compatible, so generally speaking, you can safely add faster memory to a computer that was designed to run slower memory. However, your system will operate at the speed of the slowest memory module.
In "DDR3-1600 PC3-12800"
- "DDR3" is the type (and must be the same as what your computer has)
- "1600" is the data transfer rate per second specified in millions (the technical term is "clock frequency") - "1600" here means it supports up to 1600 million transfers per second - in your case, it will be slowed down to 1066 million transfers per second since that's what your Mac is designed for
- "PC3-12800" is the name used in the memory industry - 12800 indicates a peak transfer rate of 12800 MB/s (of course, the actual performance in your case would be brought down to 8533 MB/s, matching PC3-8500).
as I'm almost locking a deal on a pair of Hynix 4gb 2Rx8 PC3-12800s (<- image reference) for my trusted mid-2009 MBP 15" A1286, the pair taken by seller from his busted unit of the same specs.
I was worried that seller's laptop broke perhaps due to the RAMs being 12800s (without his knowledge) and subsequently was disposing of the memory modules relatively cheaper than market price, and that it could do some damage to mine but. Your info, however, helps a lot towards my decision.
I hope they work on my laptop smoothly.
Cheers.