I use my 15" rmbp for work. The problem is, when I have more than 10 windows opened, the display server becomes compeltely unresponsive. The window manager feels like its working at sub 1FPS, moving windows/resizing is impossible, expose becomes useless and fans run at max speed (super loud and hot). When I close a few windows back down to sub 10, I get about 10-15fps (thanks yosemite, mavericks used to do 20-25). I am in the green for memory pressure, CPU util. sub 15% most of the time. The only way to 'fix this' is to reset the display server every 30 minutes and effectively close everything that was opened (almost as bad as having to reboot every 30 minutes). I use the machine for work, and 10+ windows is a norm (3-6 braintree windows, 2-3 atom windows, iterm, 3 web browser windows, finder, spotify, hipchat, skype, irc). Anyone else experiencing this? Would clean re-install help? Anyone experiencing this on 16gb rmbp? Please advice. I really don't know what to do, I can't afford to buy another computer because of this, but I also can't work this way (the desktop is completely unresponsive).