Hello out there!
I am having trouble with the performance of LR CC on my new iMac 27" 5k since the first day. I am very disappointed because of that...
Talking and comparing in facebook-groups raised suspicion that it might be a AMD graphic problem. Most User with older Macs (like MacBook Pro, iMac 21", iMac 27" non5k) with nVidia Graphic have no trouble with the performance. Many Users with newer AMD powered Macs do have problems!
What is your opinion out there?
Do you have the AMD graphic card drivers up-to-date?
As far as i know, there is no way to update the drivers by myself in OS X.