What are the pixel dimensions of the 27" screen? Sometimes setting very high pixel dimensions will cause Lightroom to slow down. However, a "normal" screen size 1920x1080 shouldn't cause a slowdown
thx for answer
the thing is lightroom now is slow even without the screen
also i make a new catalog with few photos same issue
the mac book pro is new and there is free 200 GB flash hard drive also the main catalog is on the flash drive !!
the resulotion is 2560 x 1440 for the screen
and it is a Retena for the mac book pro
for the previews i don't know why it is still loading some of the photos even i generate 2880 High rez and leave them for 30 days if i close lightroom and open it again it is loading some of the photos not all of them
before i don't have this issue
should i delete the previews file ? and try to rebuild them again ?
I don't know much about Retina screens, maybe someone who is more familiar with Retina can step in and indicate if this could possibly be a source of the problem.