Kingston Technology 8GB Kit (2x4 GB Modules) 1333MHz DDR3 SODIMM Notebook Memory for Select Apple iMac's and Macbook Pro's KTA-MB1333K2/8G

I bought this for my 13" Macbook pro early 2011 because it became noticeably slower when running several different apps with just the 4GB cards.Changing out the old memory cards was easily done but after taking my computer to school, it crashed a couple of time by just freezing and making a beeping noise (Very bad in a quiet library!). It also did not start up once. Removing and reseating the memory cards did not help and swapping back the old 4GB cards were the only thing that stopped the problems.I was able to get an exchange done and so far, my macbook with the new cards have always started up properly and it has not frozen up on me yet. I also able to run several programs at once smoothly. I will update if any problems occur. Minus one star because of the the bad first set but I would have only taken 1/2 star off if possible.

I recently installed Mountain Lion and noticed the system seemed to slow down a bit. The wheel would spin considereably longer than without Mountain Lion. I would wait especially long if the system had the screen saver running. Having the original memory memory in place prompted me to try upgrading to the full 8GB. I looked in the local stores (Bestbuy, etc) and realized I could probably get what I needed on Amazon. The shipment arrived today and I eagerly powered down the laptop, flipped it over, removed the 10 screws, popped out the old memory, put the new memory in place, put the screws back in, flipped it over, and powered on the machine in all of 10 minutes (if that)! I think the longest part was removing the 10 screws and making sure not to drop them that took the longest. After powering on the machine (which I didnt notice any difference), I went to the "about this mac" system report and the machine instantly recognized the memory. I did notice that the package said it was 1333 mhz, the memory cards said they were 1333 mhz, but the system report says the memory is 1600mhz. It still says there is 8GB on board, but I havent noticed any defects with the laptop. The only thing I noticed, or rather not notice, is the wheel doesnt spin anymore. My programs seem to open up instantaneously, and swapping between applications (especially my math graphing software) seems like it did before the mountain lion upgrade. My problem has been solved.Pro's: Great Price, Fast delivery, No Tax, Lifetime warranty, so simple to install (a chimp could do it)Con's: None so far. Why didnt I do this when I first got it?

After installing the RAM, my 2011 MacBook Pro worked fine initially. But after a few hours of use, it started beeping and became unresponsive. I checked the status of the RAM, and it was installed properly; performed a Disk Verify, but it still crashed. I tried re-installing the RAM, but the same thing happened. Checked out a couple forums, which all identified the RAM as the cause of the beeping and crash. Eventually, I called Kingston, after reading one of the reviews here- someone else had a similar problem. They were very helpful, and I was able to return the RAM to Kingston, as it is under warranty, and they sent me 2 new sticks, that appear to be working well.

I needed to upgrade my iMac 27" since I use Aperture & Nik software quite a bit these days for adjusting photos. I had the standard 4GB of ram that came with my iMac (2GB x 2), and it was taking longer than I wanted to "get things done". After searching through the multiple offerings here on Amazon, I decided on this memory since it's advertised as being tested specifically for Mac's, and Kingston has been a trusted name brand in computer memory for years.I installed it yesterday into the open memory slots, it works as advertised, the speed increase is worth the money in my opinion. Making adjustments in Aperture and Nik software seems to take about half or less the time it took before. I run the Activity Monitor with memory usage in the Dock so I can monitor the usage, and thus far with running Aperture, iTunes, and other software I use on average about half of the total 12GB I now have.The memory was packaged well as expected, and arrived a day earlier than the expected delivery date on the free super saver shipping.PROS📦 Packaged well🔩 Plug and play📝 Tested for Mac compatibility📈 Speeds up memory intensive applications🎨 Has that "premium memory" appearance🚚 Fast shippingCONS💰 Costs a little more than some other brandsOVERALLI'm happy with the memory, it works perfectly with my iMac. 💾💾💾💾💾 Highly Recommended.

At first I thought I had the wrong product b/c it would NOT go into the slot. I was about to return it when I started reading reviews and realized other iMac users (mid 2010) had used it. Someone mentioned how hard they'd pushed on the cards, and others mentioned turning their monitor completely upside down. (We'd just laid ours on it's back...don't do that.) SO I turned mine completely upside down. Then, I pulled (hard!) on the plastic strips that you have to pop out in order to install cards...these popped the two existing cards out a bit. (I didn't do this originally b/c I was only adding two cards, not replacing existing cards.) With the two 2GB cards popped out, I put the two new cards in so they were flush with the two old cards. While I held the monitor steady on my lap, my husband pushed hard (to the point where he thought he'd break the cards) and in they went! **Just make sure you line up the cards correctly--the little divots on the cards need to line up with the metal piece inside. Use a flashlight.** Plugged back in, turned on, extra memory showed up immediately and I saw a difference the minute I opened Firefox to place this review! (NOTE: I have the two Samsung-brand 2GB cards in that came with my iMac. I added Kingston at the advice of the Apple store rep, who said brands didn't need to match up.)

Dead easy and quick to fit, though I have not noticed a huge difference in performance! perhaps not yet put to the test of RAM intensive tasks but with 12 GB of RAM I should now have a machine that can cope with most and a much more cost effective option to Apple's upgrade

works faultlessly , easy to install ( instructions on apple site or use 'About this mac' > more info >memory tab > memory upgrade instructions ) . Kingston memory has always worked for me , a good value upgrade . Helps with future proofing your mac for a while - especially when multitasking.Bought for a mid2011 21.5" iMac running snow leopard, lion or mountain lion.

Arrived super-promptly, and fit perfectly into my new Mac. Worked straight out of the packaging and into the machine. Significantly cheaper than upgrading via Apple, too.

This will not work on a macbook pro (mid 2009). You will have to keep one 1066Mhz SO-DIMM in your mac, so one of these can work.And it's SPD write protected, so it's speed cannot be changed from 1333Mhz to 1066Mhz. This would solve the problem.

Works Great on an iMAC mid2011. Very Easy to fit and worked 1st time. iMAC seems faster but multi tasking has become very fast