I have a mid 2009 13" Mac Book Pro. I want to upgrade the RAM from 2GB to 4 GB. Can I use 1333 MHZ modules instead of 1067 MHz?

Question

The manual suggests 1067 MHz modules but my dealer stocks only 1333 MHz modules. Can I use two modules of 2GB 1333 MHz in place of the present two modules of 1GB 1067 MHz.

Answer 1

I wonder if perhaps the new ram isn't exactly right for the computer?  When you install a 2gb and one of the 4gb and go to Apple-About This Mac does it show up as 2gb or 6gb?  Just thinking perhaps the computer can't read the 4gb cards at all, so as long as one of your old 2gb cards is there to function it doesn't freeze (seems like an odd concept but I've seen it happen in PC years ago, so not sure if it's even possible with current hardware or Mac but it's a thought).
Also, double-check the sticker on your new Ram to be sure it works with your system (http://support.apple.com/kb/HT1270) thinking maybe even if you bought the correct package in the store, maybe it contained the wrong product?  You didn't say what screen size you have, but it looks as though they are all the same specs (13, 15, and 17-inch MBP mid-2010):
- Double Data Rate Small Outline Dual Inline Memory Module (DDR3) format
-30mm (1.18 inch)
- 2 GB or 4 GB
- 204-pin
- PC3-8500 DDR3 1066 MHz type RAM
I did a quick search and found this thread, same issue, so perhaps it may contain some clues as well: https://discussions.apple.com/thread/3797144?start=0&tstart=0  I noticed someone mentioned the brand or source of the purchased ram; I have personally had issues with third party or "other than what the manufacturer recommends" brands of memory over the years.  I bought mine from Amazon.com but made sure it was Crucial brand, which I've always had high success with.