-Using Lightroom, 2014 Macbook Pro Retina, runs almost instantly for all LR operations
-However, slow when applying a crop, ~20 seconds (e.g. in Develop module, crop tool, change aspect ratio, move crop area and click 'close')
-When applying a crop on different resolutions, crops in < 3 secs; great (e.g. 'Best for display' or custom res e.g. 1440x900)
-Even when using custom resolutions, retina or non-retina, (using autoscript or an app) such as 2560x1600, crop is applied in < 3 secs
-Only when using 'More Space' (1680x1050) retina option does applying crops slow down
For others with this 'slow Lightroom cropping' issue, try running your mac at different resolutions [system preferences>displays]
Any ideas why we are experiencing this odd behaviour?
I have the same problem. waiting for an answer from adobe
Try resetting the PRAM (boot from cold and hold down ALT+CMD+P+R - completely cleared my Illustrator issues and helped with Lightroom Develop Module issues.
Lightroom 6 / Lightroom CC update seems to have completely fixed this issue! Performance is fantastic