Advanced tips for improving Adobe Photoshop Lightroom Performance

I use Adobe Lightroom as my primary image management software on both the PC and Macintosh. One of my persistent frustrations has been the “creeping slowness” issue, especially on an extended shoot. For instance, on day one of my trip to Africa last year, my catalog had about 8000 images and was nice and speedy. By day 10, my catalog had grown to 30000+ images, and I was cursing it’s slowness. Compacting the catalog didn’t seem to help.

After banging my head against this problem for about a year, I’ve discovered a number of surefire interventions, organized from simple to complex. Click on for more details.

  • Rate and keyword photos using the loupe tool, not the develop tool: If your goal is just to breeze through new photos, and assign ratings and tag make sure you stay in the loupe tool. Just the mere fact of viewing photos in the develop tool takes more resources, as LR must now load up lots of data in anticipation of editing.
  • Avoid excessive rating inside of filtered views: If you are rating files by targeting a particular keyword or complex smart collection, be careful. For instance, avoid targeting a keyword such as “Africa”, and rating photos inside of it, when the “Africa” keyword has more then 5000 images.
  • Keep disk space at least 15-20% free: LR will take a larger performance hit as your disk gets more and more fragmented. At least on MacOS, keeping a healthy amount of space free will help prevent files (especially the LR catalog itself) from becoming too fragmented. I frequently can boost performance just by making sure there is a healthy amount of space free and recompacting my catalog. Of course, you can also defragment or even optimize your hard drive layout but that is a substantially more in
  • Use the catalog compaction feature in LR: This tool does work to improve performance, but its most useful after you’ve deleted a bunch of photos or otherwise caused the catalog to loose weight. If your disk is nearly full, I suspect operation can sometimes hurt performance by increasing catalog fragmentation.
  • Watch out for the metadata scan of doom: Every so often, Lightroom will decide that it has to stat() your entire photo collection. I don’t know what triggers this, but the symptom is that you will get a large amount of “at rest” reads. A tool like fs_usage will show multiple disk hits and stat() operations.
  • Purge caches: Generally, I leave my Adobe Raw Converter cache set at 10-15GB, and everything works fine. But every so often, for whatever reason, I begin to notice a slowdown when entering and exiting the develop module. Counterintuitively, clearing out this cache can sometimes improve performance. (This raises the question if my cache was too big in the first place, but without inside knowledge from Adobe this will remain an untested hypothesis.)
  • Quit other applications to free up memory for disk cache: Because LR is constantly hitting its database and thumbnail cache over and over again, increasing size of your operating systems in-memory file cache will benefit LR substantially. In MacOS, this cache is sized to whatever is left over after you add up all resident memory pages from running applications and utilities. So quitting out of Safari and Photoshop can free up this cache to help improve LR performance.
  • Optimize your disk: I’ve recently taken to running a defrag/optimization on my hard drive on a monthly basis and this has substantially improved my Lightroom performance. The symptoms I was seeing was an extreme about of lengthy disk reads when the application loaded. A quick check to iDefrag showed that my Lightroom catalog was spread out all over the disk, which was probably driving up seek times. Of course, keeping more disk space free is also a solution to this, as it will improve the ability of the operating system to find larger chunks of free space. The connection between fragmentation and slowness is amplified for large files like the LR catalog. The more the hard disk head has to move when searching around in a database file, the slower the reads will appear. Defragmenting your hard drive clusters your catalog together near one place on the disk, reducing these seek times. Similarly, keeping your previews close together with the LR catalog itself on disk should help things. A really advanced tool like iDefrag on the Macintosh can perform this type of file content localization.