Q: Mountain Lion UI Lag on rMBP !!! (Let's Make this thread serious and hope for a fix)

Remember, the rMBP doesn't even HAVE a discreet card, and yet, clearly there was one unit of the six that performed poorly over the rest. You know how the demo unit run those Apple demo videos? Well this one lagged to shame while the other five screamed. I didn't see any 15" rMBP's on display, but something tells me this problem goes beyond the graphics processor :(

Sorry correction, I meant to say the 13" rMBP doesn't have discreet video card.

Sorry, but replacing parts is not going to fix anything. I'm on my third replacement. Fresh out of the box, everything runs well, but within the first day or two, the problems come back.

Then it's hopeless. Return your rMBP and buy something else.

That, or wait for an update to fix the problem, or settle with the problem. Besides, I think most of us on here are beyond return.

Seriously, if I have to fix my computer three times without resolve, then it's time to either post it on Craigslist or get Apple exchange for something completely different, like a high resolution anti glare MacBook Pro.

Tell me about it. I'm not impressed with this product line at all. Aside from all the issues mentioned here, my first had a defective battery. My second had a bad hinge and when I was directed to take it to the Apple Store, their screwdriver slipped and scratched a nice gash into the aluminum and then said they couldn't fix it. Just got my third unit a few days ago and something very large is loose inside of the body... it feels like either the battery is loose, or one of the boards. Either way, it's not good and rattles when I type. I can't seem to catch a break with this thing. I will once again visit the Apple Store today, and will cross my fingers that the geniuses don't mess something up. Meanwhile, UI lag on all three devices, as well as various major anomalies in Safari during web browsing. I've never had such a poor exerience with a company.

Regardless, all that's been said and done, the retina display is still the most remarkable display ever made. Truly I don't even want to work on a 17" 1920x1200 screen any more.

For me, the better way to avoid these lags is to use a non retina screen resolution, as 2048x1280 with using a soft like SetReX. I've totaly given up the idea of a fix… 

So pitiful, but that's life. Apple is no longer what it was…

I was just talking about my wife regarding the same thing. She's like "see if you can get your money back and get a standard Macbook Pro like mine" and I'm like "once you spend months looking at 2880x1800, everything else looks like garbage". It's frustrating having the best laptop I've ever used with some of the stupidest problems ever to face a laptop. Can't wait for the second generation of this thing, assuming it has discreet graphics and isn't garbage like the current 13" rMBP.

As a few others have voiced. This problem is prevalent on all the machines. I'm on my 3rd replacement. The first two had awful buzzing sounds coming from the motherboard, the next had a hinge problem, now I'm on my 4th that needs a screen replacement because of a screen burn in issue they are well aware of. But what has been consistant on all the computers is the horrible UI lag and choppy graphics - even in the apple store all of their machines including the new 13 inch retinas had these graphics issues.

The problem is not prevalent in all machines! As I mentioned earlier on this thread I have a colleague with the same identically BTO spec'd rMBP and he's having absolutely no issues. He can play Warcraft for hours without any low frame rates or show any lag in any of his browsers. There's one component that we haven't even considered, and that's the SSD. Like a broken hard drive, a defective SSD can also cause software related problems. I got apple to have a look at that and possibly replace that as well. I'll be getting back my rMBP from repairs later this afternoon and I'll let you all know how that went.

I've played some games on my computers (starcraft for example) I didnt have problems... the problems I have are with NORMAL day to day use things like web browsing, checking e-mail, switching between desktops, and using Aperture / iPhoto.

Its very apparent that some people just either dont notice this lag or are not letting it bug them - but lets be clear, every computer I have tried and its over 15 retina MBP's ALL had these issues 13 and 15 inchers alike. Having an epidemiology background and being well versed in statistics I can tell you that having 15 computers that all exhibit a problem and 1 (you're friends) that does not means he is an outlier and either his machine is defective (for working properly) or he isn't being honest of his experience. For example, my girlfriend also has a retina MBP she doesnt notice the lag that much, but when I test it - its exactly the same as mine... some users are not that critical of their machines but for $3000 having a smooth polished user experience is a absolute minimum that Apple has not achieved.

Well put, Ahzari. Couldn't have said it better myself. I also have a classmate who reports a flawless experience, but when I look over his shoulder I see an even worse UI experience than that of my own.

Alright, let me tell you how a properly working Mac under lion or Mountain Lion should run: when you restart your computer, once you pass the grey Apple startup screen, do you see your screen do a slight shift in color, THEN the desktop wallpaper zooms/glides into view? Of all the defective rMBP's that I've seen so far, none of them do the "glide-into-the-desktop" effect, right after startup it blinks out black for half a second, then the wallpaper instantly appears, no smooth "gliding" effect. Of all the correctly working rMBP I've tested, the one's without lag have the "gliding" desktop at startup, no blinks or flashes.