Hello guys. Yes this is another one of those threads. But I really still encounter UI lag even with GT650M activated. The thing is the lag is "weird". No I am not talking about safari "scroll lag". That is non existent anymore. I am talking about general UI lag. I will try and explain. If I have 3-4 windows open for example safari, itunes, iphoto and finder and I try and use mission control there is lag... not much but enough. If i try to swipe between desktops sometimes it is silky smooth but then it gets jerky and laggy. Sometimes I swipe 2-3 times and it is super smooth but if i continue swipe back and forth, eventually it starts to lag. The same happens in launchpad as well. Super smooth, then after a few swipes, boom... lag. Same with notification center... smooth, then lag. I have reset SMC and PRAM that doesnt make any difference. I have tested the machine thoroughly in benchmarks and the resulta i get are on par with the performance expected, both in terms of cpu and gpu so there appears to be no fault at all. Please dont post just to say that your retina macbook pro is super smooth. I want to know if other people share the same experience as I do, and whether there is a solution. I know the frames per second thing is a subjective matter that differs from people to people, some consider smooth performance what other consider laggy, but I think I explained quite well my issue. The lag comes after doing the same thing continuously. Sometimes it is laggy when i start the swipes, then it gets smooth then laggy again. It happens prominently with mission control, spaces, launchpad and notification center. Please share if you have the same issue. I thought Mavericks where supposed to eliminate UI lag, but I dont have such an experience.