Crucial 8 GB Kit (4 GB x 2) DDR3

Crucial 8 GB Kit 4 GB x 2 DDR3 1066 MT/s PC3-8500 CL7 SODIMM 204-Pin for Mac CT2C4G3S1067M ... 4.8 out of 5 stars CONSUMER REVIEWS(31) Increases system performance Compatible with Mac systems Every single module extensively tested at the component and module level for functionality Meets or exceeds Apple's own quality requirements Easy installation Available in DDR2 and DDR3 SODIMMs in capacities up to 8 GB DDR3 modules include lead and halogen-free technology Deal Price: $89.99

Description CT2C4G3S1067M is an 8 GB kit consisting of (2) 4 GB DDR3 Notebook modules that operates at speeds up to 1066 MT/s and has a CL7 latency. It is Unbuffered and is non-ECC. It conforms to the industry standard SODIMM layout of 204-Pins and is compatible with computers that take DDR3 SODIMM memory. I was somewhat reluctant to order these as people were saying you may not see much improvement. I ordered and I am pleased with how much quicker the computer seems(just based on what i have done with some photo & video programs) and its just seat of the pants timing but after this manner years of using the programs less lag and spiraling wheel. I ordered another set for my work system. I would recommend these. Firmware was already updated with Mountain Lion. Mac recognized the 8GB instead of just 6GB. Mac has been running a lot faster and handling multitasking with great ease. I would recommend this to anyone who is looking into upgrading their Mac's. I bought this upgrade to the 2 x 2GB sticks in my Mid-2010 Macbook Pro 15" i5. I had no compatibility issues and it produced a very noticeable speed boost. If you feel your Mac is in need of more memory, I would recommend the following to know if your RAM is the issue: Open Utilities folder -> Open "Activity Monitor" -> Click the tab at the bottom labeled "System Memory" -> Just below that, you should see a few sets of data...The important ones are:"Free" : If your "Free" memory is low (or 0!) you probably need more memory."Page Outs" : If the "Page Outs" is high, this means that your computer is using hard disk rather than RAM for memory functions and produces a severe loss in speed."Swap Used" : This gives a rough estimate of how much hard disk is used for RAM. This will give you a rough idea of how much RAM you should add. i.e. if this is 4 GB, then you should add at least 4 GB...