Let’s see if you recognize the symptoms: changing pictures in the library becomes painfully slow, selecting more than one image takes ages, all that while the developing module remains quite quick in use.
That’s the dreaded Lightroom 5 slow-down.
I tried every suggestion read on various forums to cure it:
– deleting preferences files (on Mac)
– showing only the “default” metadata in the gallery view, and not iptc & exif
– creating smaller catalogs, like one for every year*
and others I forgot.
Until on an Adobe forum I finally found a solution. Are you ready?
Just do not have too many develop presets. That’s it.
Sooo simple… If you, like me, have accumulated and / or created too many develop presets these will cause Lightroom to slow down to a crawl in the gallery mode. But, strangely enough, not in the develop module; this is the reason I’d never thought of looking at them as suspects.
If you don’t want to actually trash your presets just copy them in a separate folder on your hard drive, leaving available in Lightroom the ones you actually use more often.
To give you an example, I went down from maybe 6.000 / 7.000 presets (I accumulated most of them when I bought Lightroom 2) to way less than 1.000 (mostly film simulations in various flavors, Lightroom standard ones, plus my own presets).
Should you ever need a discarded preset just copy it back into Lightroom develop preset folder, restart the program, and it will be available again.*this though should actually work as a cure for Lightroom 3 and 4 slow-downs