Speed up Lightroom by splitting up your image previews

The article contains information that may speed up Lightroom by spreading disk reading load across multiple drives. It achieves this by utilising symbolic links within windows. This simple approach does not require any advanced knowledge of windows, Lightroom, or involve RAID or other such technologies.

So one day I was running out of space on my f: drive, something that happens a lot as it is a small SSD and I have a bunch of photos.

Looking at the layout of my Lightroom folder, it was looking kinda messy, but I noticed that my previews and smart previews were taking up a heap of space. About 250gb and 100gb respectively. Being a bit of a hoarder, I didn’t want to delete any previews or smart previews, what if I needed them, what if they make Lightroom faster. Well, they do, as my photos are on a remote drive.

The Hypothesis

The solution is to utilise the windows equivalent of symlinks. My hypothesis (after reading how to create them using mklink.exe) was to split the previews onto two separate drives. Drive e: would contain the smart previews, and drive f: would continue to contain the Lightroom catalogue (and folder) and previews folder.

Obviously, I needed to copy the files from my f: to my e:, so trusty robocopy.exe was used.

e:\>robocopy /mir source_folder destination_folder /mt:16

Now that all the boring bits are out of the way it was time to rename the old directory to ensure that you keep it for the moment, but it is not used by Lightroom post symlink (I added .old to the end)

Creating The Link

Now all that was to be done was to utilise mklink.exe to create the symbolic link from the smart previews on drive e: to the catalogue directory on drive f:. eg:

mklink /j destination_dir source_dir

Once the command was executed, windows explorer revealed the linked directory (see the arrow)

It was now just a case of moving the .old directory (what I had renamed my original smart previews folder, before making the link) to another location leaving the directory clean (see below).

Now to test, using the library ->previews -> build smart previews from within adobe lightroom I can see that my f: drive is fairly quiet, but now my e: drive is working quite hard.

I hope you find this little tip helpful, or at least a little interesting. I am sure it is not supported by Adobe, and you probably shouldn’t do it. That said, see how you go..…:)

Notes:

• I take no responsibility for the information presented here, I use it for my own benefit and am sharing it in the hope it will help others.
• I have no proof that this speeds things up, it feels faster to me, and it spreads the loads across drives, but I have not spent a lot of time measuring it.
• Use at your own risk, as if you lose your previews, it might take a long time to recreate them, especially if you have been collecting them over the years.
• Each time Lightroom is upgraded to the point that it needs to re-do your catalogue file, it will re-create your previews directory, which will NOT be over the symlink. It will create your “catalogue-2 smart previews.lrdata” directory in the catalogue directory.
• I used the robocopy command and rename folder to ensure that I didn’t lose any preview files, and if lightroom complained I could go back to what I had before (without having to copy back)
• I’ve been using this for a few years now, and I personally haven’t had any problems.

About the Author

Not much is known about Paul Snow, except that he was frustrated with his Lightroom Performance. We thank him for his service. This article was also published here and shared with permission.

---