Hello, A little bit of context: I've used Macs since 2009 to 2012, but getting a powerful mac machine was very expensive for me at that time, so I got a lenovo i7 2.4ghz (4700MQ), 755m SLI, 16GB ram and a 256gb ssd. The machine was more than wonderful, there was nothing I could throw at it, whatever I did everything was smooth. As a plus, it was a very powerful gaming machine, but I did not care about that too much. Now recently I felt the need to have a better screen, longer than 1.5hr battery life and ofcourse I had to make iOS apps so I had to suck it up and get a mac, because I didn't want to waste time with hackintoshes or virtual machines. So I found a sweet deal, a second hand laptop, late 2013 15" retina, i7 2.3, 256gb, 16gb ram (iris pro only). Something quite decent for development. Laptop was 10/10, newly replaced battery and screen. It was like brand-new. Now, back in the macOS world, things are beginning to get choppy. (Using Sierra) - Chrome is not butter smooth, when scrolling I see it struggling to render - Using mission-control when an external display whole system becomes choppy - Using mission control with no external display sometimes is choppy (less often than with ext. display) - Scrolling down on a PDF is worst experience, especially with Adobe Reader - Resizing windows is laggish as hell I resetted PRAM, SMC. I tried the trick with "disabling brightness adjustment". There are no CPU hogs. And no CPU spikes during my usages according to Activity Monitor. I was always with the impression that macOS is built for the hardware macs offer. And this baby is an i7 and struggles with common tasks ? Like WTF has happened... I also have a macbook air, late or early 2015 don't remember, my wife uses it. That works butter smooth, for common tasks. It feels snappier than this retina powerhouse. Maybe I'm a pretentious f***, but I shouldn't be getting any slowdowns, it irritates me. It's something I did not have on my big ol' lenovo. Question is: is anyone else experiencing this ? Is there any fix to it ?