Many people on the web say that you shouldn’t have more than 10,000 (ten thousand) photos. Then they go on to explain that after that many photos, Lightroom suddenly slows down, so it must be the maximum. So let’s look a some of the facts:

  1. Lightroom does NOT store photos. It’s not just semantics, there are many implications like when backing up your catalog, you are not backing up your photos….
  2. Lightroom stores information about your photos.
  3. Lightroom uses a database called SQlite.
  4. SQlite is a memory resident database. This means that all the information is stored in memory, kind of…

Consequences

The 2 important key points are:

  1. Lightroom stores information about your photos.
  2. All that information is stored in memory.

This means that the more information you have, the lower the number of photos you can have in your catalog. The more descriptions, the more keywords, the more edits, the larger the catalog.

You can shrink the catalog by:

  1. Clearing the history
  2. Backup your catalog and restoring the backed-up catalog on top of the existing catalog.

  3. You can increase the physical RAM on your computer, but as a 32bit operating systems Windows or Mac, you can only use up to 3Gb of RAM, to access more than the 3Gb you will need to switch to 64bit operating system.

  4. You can close other applications and this will free the some of the memory available to Lightroom.

I still have to see a catalog use more than 3Gb of memory, even if the catalog is larger:

  • The current grid/collection with the thumbnails are kept in RAM
  • The current photo being used in the Develop module
  • The photos used for the output, either to the printer or to the web/flash/viewer

Conclusion

There is no definite answer as to what the maximum number of photos you can have in a catalog. It will depend on:

  1. Your hardware 32bit/64bit and the amount of RAM available
  2. The type of information you store in the catalog
  3. Your personal style like having many programs opened at the same time…