Upgrade to 8GB RAM In Desktop/ Laptop (4GB Stick) | eBay
Does Memory Matter? 4GB versus 8GB versus 16GB in Gaming | The Tech Buyer's Guru
OWC 8 GB (2 X 4GB) ram PC8500 DDR3 1066MHz sodimm 204-pin Memory Upgrade Kit, (OWC8566DDR3S8GP), Compatible with MacBook Pro, MacBook, Mac Mini and iMac at Amazon.com