My gf's late 2011 MBP 2.4GHz i5 13" non retina has original 4GB RAM and I was looking to upgrade to 8GB but I noticed at online store that Corsair 2x4GB kit was more expensive (78) than a single 8GB stick (60) - so why would I not go with replacing one stick for 10GB (original 2 + 8). I know the thoughts about matched pairs running better but many users here report no issues with un-matched pairs. I believe this MBP can handle upto 16GB RAM and is non-soldered. Machine is running Mavericks. I've done some searching but didn't find anything, apologies if this is a duplicate thread. I've put Corsair RAM into my Mini so happy with that brand.