Problem: I have a base 2.3 Ghz 8GB 15 inch (Samsung display and SSD) Retina which I got for a great deal. I absolutely love the machine, it is better in every way than my 2009 cMBP, but it is also horrible in one aspect. That being, UI lag of normal every day operations. Depending on how you use the machine you might or might not notice it. Here are some cases where I did notice it. When viewing some Mails in the Mail app, I sometimes got the spinning ball, while trying to preview a pdf on specific message. Using Terminal with medium opacity, I could notice a lag with that application. Mind you, if you have opacity at 100%, there would be no lag. Safari has lags on certain websites, however latest webkit build fixes that. I was seeing huge memory usage. WindowServer process was using 500MB+ of memory, every windowed application seemed to be using more memory. From reading around the web, I knew the lag was tied to the software and cpu speed of the rendering threads and processor. But the (late 2012 2.8Ghz) is at most 15% faster than my base 2.3 Ghz. Considering I paid around 1899 minus 140 of best buy credit which I used towards a GPS, I got a great deal on the Retina, that I would be giving up by upgrading. There is a huge Apple Discussion thread (https://discussions.apple.com/thread/4148076?start=720&tstart=0) on it. Solution: Then I saw this thread on reddit -> http://www.reddit.com/r/apple/comments/vi9yf/set_your_retina_macbook_pros_resolution_to/ That app seems to work. Right now I am on 1680x1050 non HiDPI resolution. The lags are gone. WindowServer on average takes 100MB of memory, and I have not see it go above 200MB. Most processes that have UI elements are using less memory. It now seems my 8GB is fine. I am now seeing almost the same memory usage as my late 2012 2.6Ghz Ivy Bridge mac mini, in terms of how much memory each process is using. The fonts and text are not as great as the HiDPI default resolutions, but they are better than the cMBP. The display on retina is of course much better is by default no matter what resolution much better than any cMBP. I hope no issues pop up, but so far using a non HiDPI resolution on the Retina, seems like the only solution for lag. Note: You just have to change the resolution once, through the app. After that you don't need to the app running unless you want to change the resolution. The settings stick through even if you restart. You can also change it back to retina resolutions by going to System Preferences -> Displays or through the app. Source code is contained within the app folder in RDM->Contents->MacOS I am guessing if Apple doesn't come up with a way to fix the lag issue in either software or hardware, they can make non HiDPI resolutions available in system preferences for those who want "more power". Knowing Apple that is like conceding defeat, and that would be their last possible option.