Crucial CT2K8G3S1339M 16 GB Kit (8 GB x 2) (DDR3L, 1333 MT/s, PC3-10600, CL9, SODIMM, 204-Pin, 1.35 V/1.5 V) Memory for Mac, Green

I bought two lots of these to beef up my late 2013 27inch iMac i7 to 32GB. They worked perfectly after waiting for the hidden POST to complete. When you first plug in an iMac it goes through a hardware test cycle, keeping a record of any changes. When adding 32GB it took about two minutes for the iMac to check the RAM before it would turn on. I have seem many people complain their iMac did not work after upgrading the RAM; it was more likely they did not patiently wait for the system to finish updating its spec details. So here is the sequence whenever you change RAM on an iMac, even if downgrading to use the original RAM!1. Disconnect power.2. Open door to memory slots and pull down the memory holder as shown in the iMac manuals.3. Remove existing RAM, carefully noting which slots are populated AND the module orientation.4. Add new RAM to either the same slots OR all slots if you are adding four modules, carefully checking each module is properly oriented and fully seated. Unlike PC's, iMac memory slots are somewhat 'sloppy' - don't expect a satisfying click.5. Push the memory holder back in to place. If it won't go back properly, check the modules are correctly oriented and fully seated. 6. Close door to memory slots.7. Plug in iMac and make sure mains power is on, but *DO NOT* press the power button.8. Go make a cup of tea. (Important)9. Come back and click the power button.10. Bong......In future the iMac should not need as long to start after plugging in to the mains; only the first time is the issue.I hope this helps someone.

Fast delivery and easy to fit. Increased the performance of my MacBook Pro for a very reasonable cost. If it gives me another few years of useful life of the computer then it's been worth every penny. Good trusted manufacturer also, Crucial are a market leader in ram chips. Highly recommended.Please hit "Yes" below if you found this review helpful. Thanks!

This memory is listed as "Mac compatible" which I figured is just a marketing blurb and all of its specs matched what I required for my (Windows) laptop, so I figured I'd take the chance and buy these after my first attempt failed with a different brand of RAM, some time prior.I was skittish about booting with a different amount of RAM from hibernation, so I shut it down completely and performed the replacement. Pretty standard stuff. As another reviewer has mentioned, be sure to wait a while for the initial boot after RAM installation to complete!! It can take a while, your system/the RAM is not necessarily broken. Maybe have a snack or take a peek at the television or phone for a few minutes while your computer does its thing. After the initial lengthy boot, you will have your normal boot times back again on subsequent boots/restarts.Anyway, this new RAM works great! I finally have enough memory to accommodate all of the programs I like to run simultaneously, such as monstrous browser sessions that can easily eat 2GB of memory a piece. My system would slow to a crawl on 4GB, as it simply wasn't enough. Now it's perpetually responsive.As with all RAM upgrades though, you'll only notice a particular performance increase if you didn't have enough to start with, but you could always use the spare memory as a RAM drive for ludicrous temporary storage speeds.For determining compatibility, it can be slightly complicated. If you look up your system's processor/motherboard on the manufacturer's site, it can usually give you precise details on what type of memory - and how much of it - is compatible with your system. It's what led me to this product in particular. I think Crucial also has a web-app that can help you determine compatibility by providing it with your computer's model.Overall, very pleased with this purchase.

My late 2012 27” iMac was really slow. It would take a few seconds to open a new tab, switch between windows or even type a key.I thought it was overheating or my computer is just getting old and was thinking of buying a new one. But I bought 2 of these (8gb x 4) and now my computer runs like it was new. Upgraded from the standard spec of 2x4gbInstallation is easier than installing flat pack Ikea furniture, just google it and you’ll find instructions on the Apple website with picture guides.Not sure if it’s suitable for your Mac? Go to the Crucial website and you can either type in your model number or install their app which will read your system and tell you which stick you need so you can’t go wrong.Worthy investment/upgrade

Thought about replacing my mid-2012 13 inch MacBook Pro, but no significant bump in performance or features seems to be on the horizon from Apple. Decided to upgrade the existing machine with new RAM. Easy to install, has improved the performance of my mid-2012 13 inch MacBook Pro significantly. Great value. Just need to get the 00 Phillips screwdriver to remove the back cover without damage and jobs done!

I have 2, 27 inch iMacs and wanted to upgrade the RAM on both of them.I went onto the Crucial website and having downloaded the Crucial app I was informed which memory upgrade I required specific to my Macs.The Crucial website directed me to the Amazon website where I bought 4 x 8Gb RAM.I upgraded both Macs and one of them crashed straight away and ended up needing a new hard drive. The other one kept crashing but once I re-inserted the original RAM, the computer started working again. I have tried placing the RAM in different slots.I now other people who have had no issues with Crucial so maybe I am just unlucky to have 2 separate machines and the RAM fail to work on either machine. I have since upgraded one machine with genuine RAM and will have to wait until I can upgrade the other machine.