A while back I wrote about how slow LR was when using gradients and brush tools. Even on my 8-core MacPro, the beach ball kept on spinning forever. Today, as I was watching the L-L video “Where are my #$$$”% images”, I realized that I had turned on the “Automatically write changes into XMP” option. This makes LR write every single movement on my sliders into the XMP sidecar file (or the DNG file) as I do the movement, and the slowdown is caused by the disk bandwidth. When I turned off this option, LR in snappy, and I am happy.

So, go into the catalog settings and uncheck the “Automatically write changes into XMP” option inside the “Metadata” tab. You should also go into the “View Options” under the “View” menu, and tick off the “Unsaved Metadata” checkbox. That way you will get a small arrow on each photo that contains unsaved metadata. Every once in a while, and at least every time you quit the session, select those photos and hit Cmd-S. You will not lose work even if you don’t save, but then the metadata is only stored in the LR database file, and not as part of the image file. If the metadata is stored in the image files, you will get back everything if you reimport them into a new catalog, which is good if the lightroom catalog gets corrupted.