Does 1600 MHz Memory Offer Higher Performance than 1333 MHz Memory?
Upgrading your memory to 16GB in the 2011 - early 2012 model MacBook Pro?
The 2011 MacBook Pro models are spec'd by Apple to run 1333 MHz memory, but the motherboard supports 1600 MHz memory, which OWC now sells for the latest models (which spec 1600 MHz).
Get 16GB of 1600 MHz memory at OWC, for under $170 as this was written.
Testing Photoshop CS6 using the 2011 17" 2.5 GHz MacBook Pro shows that 1600 MHz memory runs about 2% faster than 1333 MHz memory (for in-memory operations). Of course it could be 0% in some scenarios and 3% in others, but that’s probably about it— don’t expect more than 3% at best.
It’s definitely not worth worrying about if you already have 16GB of memory, but if you’re upgrading a 2011 MBP to 16GB, you might as well grab that extra 2% speed (that’s akin to 2.55 GHz instead of 2.5 GHz, to keep things in perspective!).