In prepping this series of articles, I read much of the information already published elsewhere. Some of the suggestions work. Others are complete myths. Some of the advice (including in my old blog post!) is simply outdated. Some suggestions can even make Lightroom slower. These are the main ones to avoid…
Myth #1: GPU – Everyone should turn it off (or on)
I’ve seen many posts saying that the “Enable Graphics Processor” checkbox in Preferences > Performance should be turned off. I saw almost as many saying it should be turned on. The reality is, there isn’t a blanket ‘best setting’ that applies to everyone.
The correct setting for your computers depends on:
1. Your graphics card – you need a card released in the last couple of years, with at least 1GB of VRAM (ideally 2GB) and Open GL 3.3 or later, and even then, some cards are not supported due to driver issues.
2. Your graphics card driver – there are some horribly buggy drivers out there, which can cause more Lightroom problems than they solve. Check for updated drivers on the card manufacturer’s website (Windows) / Software Update (Mac).
3. Your screen resolution – you’ll see the greatest benefit on high resolution screens (retina, 4K, 5K). If you’re using a lower resolution screen, you may find Lightroom faster if you leave GPU disabled.
4. Your usage – Develop is the only module with GPU acceleration, and even then, it’s not the whole of Develop (yet). Most global edits have GPU acceleration, but the adjustment brush and spot tools don’t (again, yet).
5. Your requirements – there are compromises, as it takes time for the CPU to pass the data to the GPU, resulting in slower loading times. If loading time takes priority, leave it turned off.
In short, if you’re using a standard resolution screen, you probably want to turn it off. If you’re using a 4K or 5K screen, you probably want it turned on. If you’re using a smaller retina/HiDPI screen (e.g. a MacBook Pro), try it on and off and see which you prefer.
Myth #2: Render 1:1 previews to speed up Develop
I saw loads of recommendations to render 1:1 previews in order to speed up loading in the Develop module… however pre-rendered 1:1 previews aren’t used AT ALL in the Develop module. There are some good reasons to render 1:1 previews, such as quickly zooming in the Library module, but they won’t help in the Develop module.
We’ll come back to where different types of previews are used in a future post, but if you’re wondering about the complete preview loading logic, there’s a flow chart diagram on pages 553-554 of my LRCC/6 book.
Myth #3: Make the Camera Raw Cache huge
In my 2009 blog post, I recommended enlarging the Camera Raw (ACR) Cache size in Preferences > File Handling to 50GB saying, “Bigger is better!” Then, in Lightroom 3.6 and later, the cache format was changed and compression applied, meaning the cached files now take up a few hundred KB each, instead of multiple MB, so you can now fit a lot more cached images into the same amount of space. (If you want to understand the Camera Raw Cache, including ways to preload it, see pages 556-557 of my LRCC/6 book.)
I’m still seeing lots of posts saying to enlarge your cache size to 75GB, or even as much as 200GB. For most people, it IS worth enlarging the cache from its 1GB default, which would only hold around 2000 of your most recently viewed photos. On the other hand, 75-200GB is overkill for most people. You’d be better off with a 5GB-10GB cache on a fast drive (e.g. SSD) than a much larger cache on a slower drive.
But there’s one more thing. Since Lightroom CC 2015.6 / 6.6 added intelligent Develop caching, if you’re slowly stepping through the photos consecutively in the Develop module, the full resolution data is preloaded in advance, negating the need for the Camera Raw cache. So it’s only really helpful if you’re skipping around in Lightroom, or you don’t have enough RAM to hold full resolution cached data.
Confused about all these previews and caches? Don’t worry, we’ll come back to them in more detail in the Previews & Caches post, including an even better trick using Smart Previews instead of the Camera Raw cache.
Myth #4: Use loads of little catalogs
Another frequent “solution” for performance problems is using breaking the library up into multiple small catalogs. To be fair, a few things are slightly slower on a big catalog – most notably, opening the catalog and backing it up, and updating smart collection counts can slow things down on big catalogs (although there’s a solution for that in a later post). But let’s just define big catalogs: 1 million photos is a big catalog, 50000 photos is a small catalog.
These slight delays in opening and backing up are easily offset by the lack of hassle trying to search and maintain multiple catalogs, and the confusion that can result.
If you’re a high volume working photographer, there are some arguments for multiple catalogs. If you’re shooting thousands of photos a week, then a catalog per year or a working and archive catalog can be a good compromise. Or if you can’t risk the Jones wedding party seeing the photos from the Smith baby session, perhaps one catalog per job. BUT for the majority of photographers, multiple catalogs create far more problems than they solve. Just optimize the catalog regularly, and keep it on a fast drive.
Myth #5: Delete all of your previews
The final suggestion I frequently see is to empty Lightroom’s caches and delete previews regularly. But stop and think about that suggestion a moment. Lightroom has to display previews, otherwise you’re looking at a blank screen. So which is quicker? Loading a small JPEG preview file from the hard drive, or loading a full size raw file and applying complex calculations to it? If you’re unsure of the answer, trust me, loading a small JPEG preview is much faster! So why would you want to throw away all of the previews you’ve already rendered, and force Lightroom to do all these complex calculations again?
There are some circumstances in which you might need to delete previews. If the previews are corrupted (shown by an error message or lines/dots/strange colored areas appearing on the photos, or if the wrong preview is being displayed), then you’ll want to trash the preview cache. Or if you’re desperately low on hard drive space and can’t remove any other files, then you may want to trash the preview cache.
If you do delete your previews, remember that Lightroom will have to build the previews all over again the next time you try to view them, which will make Lightroom slower. To save staring at a loading overlay, you can re-render the previews overnight by selecting the photos and going to Library menu > Previews > Build Standard Sized Previews.
That’s the main Lightroom Performance myths, so next week, let’s talk about hardware.