How to Make Lightroom Classic Run Faster

by Andrew S. Gibson
How to Make Lightroom Classic Run Faster

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Lightroom Classic is an amazing application that helps you organize and develop your photos much faster then using a program like Photoshop.

But there are times when it slows down, most noticeably when rendering previews or if you are running low on space on your primary hard drive. These tips will help you configure Lightroom so it runs as fast as possible on your system.

First, let’s look at some of the common speed-related problems you may encounter in Lightroom Classic.

Problem: Full-size previews are slow to render in the Library module.

Solution One: Build 1:1 Previews when you import your images into Lightroom Classic.

This slows down the import process, but it means that you won’t encounter delays when you’re using Lightroom to preview photos. If you have a lot of photos to import, you can leave your computer to build previews overnight, or do it some other time when you don’t need to use Lightroom for something else.

The key setting is Build Previews, which you’ll find in the File Handling panel in the Import window. Set it to 1:1. This tells Lightroom to build full-size previews to use in the Library and Develop modules. It does so as it imports the images and adds them to the Catalog.

How to make Lightroom run faster

Lightroom also creates Minimal and Standard size previews at the same time, which helps explain why building 1:1 previews takes so long.

You can speed up the process by setting Preview Quality to Medium instead of High. You’ll find the setting for this under the File Handling tab in Preferences.

How to make Lightroom run faster

For a quicker import set Build Previews to Standard. Lightroom creates smaller previews designed to look at on your screen, but not for zooming. This is a faster option if you want to look at your photos in the Library module without zooming in.

How to make Lightroom run faster

Before you use Standard Previews, go to the File Handling tab in the Catalog settings (Mac: Lightroom > Catalog Settings, PC: Edit > Catalog Settings) and set Standard Preview Size to Auto. This tells Lightroom to build previews that fit the pixel width of your monitor. For example, there is no need to build Standard Previews with a width of 2880 pixels if you are using a laptop with a monitor that has a width of 1280 pixels.

How to make Lightroom run faster

Solution Two: Build Smart Previews when you import your images into Lightroom Classic.

Alternatively, tick the Build Smart Previews box and set Build Previews to Minimal. Smart Previews are the only previews that Lightroom can use in both the Library and the Develop modules. They are quicker to build than 1:1 previews and also make the Develop module run much faster.

How to make Lightroom run faster

The only drawback of Smart Preview is that they are not full-sized previews (they measure 2540 pixels along the longest edge). If you need to zoom into your images at 100% magnification in the Library module then you need to build 1:1 previews.

You can learn more about Smart Previews in The Ultimate Guide to Using Smart Previews in Lightroom Classic.

Solution Three: Build Previews for images that have already been imported into Lightroom Classic.

There may be times when you don’t want to wait for Lightroom to build previews while importing images. Or you may need to build previews for images that you’ve already imported.

It’s also possible that you have built 1:1 Previews in the past, but that Lightroom has deleted them.

Full-size previews take up a lot of hard drive space so Lightroom is set by default to delete them after 30 days. You can change this in the File Handling tab in Catalog Settings (Mac: Lightroom > Catalog Settings, PC: Edit > Catalog Settings) if you want to. But please avoid setting it to Never – otherwise you will end up with a huge previews file as your photo collection grows.

How to make Lightroom run faster

Build 1:1 Previews for previously imported photos by selecting the images you need previews for in the Library module (you can select an entire Collection or Folder if that’s quicker) and going to Library > Previews > Build 1:1 Previews.

The procedure is the same for Smart Previews, except that the menu option you need is Library > Previews > Build Smart Previews.

How to make Lightroom run faster

Note: A high resolution monitor (around 2560 x 1600 pixels) may also slow Lightroom down. Reducing the size of the Lightroom window, or using the 1:2 or 1:3 zoom views in the Library module, should allow Lightroom to work faster.

Problem: Full-size previews are slow to render in the Develop module.

Solution: Convert your Raw files to DNG and check the Camera Raw Cache settings.

First, it’s important to understand that 1:1 Previews are used in the Library module, but not the Develop module.

Develop module previews are built by Lightroom on the fly. There isn’t a way to get Lightroom to build them before you enter the Develop module. But there are still ways to speed up the process.

1. Convert your images to DNG when you import them into Lightroom Classic.

DNG files are smaller (saving you hard drive space) and (if enabled during the conversion) contain Fast Load Data. According to Adobe, DNG files with Fast Load Data render up to eight times faster than those without it. You can enable Fast Load Data under the File Handling tab in Preferences by ticking the Embed Fast Load Data box.

How to make Lightroom run faster

My article How to Make Lightroom Classic Faster Using DNG goes into using DNG in Lightroom in more detail.

2. Check the Camera Raw Cache Settings under the File Handling tab in Preferences.

Lightroom uses this cache to speed up the process of creating Develop module previews. Adobe recommends you set it to 3 GB or higher. Try a setting of 10 GB or 20 GB for optimum performance.

It’s useful to know that from Lightroom 6.6 and Lightroom CC 2015.6 Lightroom builds Develop module previews for the photos in the Filmstrip either side of the one you are working on in the background (this is called intelligent Develop Caching). That makes it quicker to move from one photo to the other if you’re working sequentially through the images in a Collection.

How to make Lightroom run faster

Problem: Lightroom Classic slows down after extensive editing in the Develop module.

Solution: Check your workflow to see if it’s slowing Lightroom down.

Are you making lots of local adjustments? The Spot Removal tool and the Adjustment Brush are not designed for hundreds of adjustments. Adobe recommends that you use Photoshop instead if you need to modify an image so much.

If you have made lots of local adjustments then the History panel may be slowing Lightroom down. You can clear it by clicking the X icon in the top-right corner.

How to make Lightroom run faster

Adobe recommends that you carry out processing in the Develop module in the following order for optimum Lightroom performance.

You don’t have to use the tools in the right-hand panels in this sequence – you can stick with the workflow that you are most comfortable with. But it’s useful to know.

1. Spot healing.
2. Lens corrections.
3. Global adjustments such as white balance and exposure. These can also be done first.
4. Local adjustments such as Radial filters and the Adjustment Brush.
5. Detail corrections such as noise reduction and sharpening.

Other ways to make Lightroom Classic run faster

There are a few more things you can do to make sure that your computer system is optimized for Lightroom.

Check your hard drive space

The most important is to make sure that you have enough free hard drive space. If your computer’s main hard drive is running low on space then Lightroom will slow down (and so will any other programs you are running).

Your main hard drive needs to have at least 20% of its space free for Lightroom to work at its optimum speed.

If you are running low on hard drive space Lightroom itself may be the cause. For example, when is the last time you checked the folder where Lightroom makes backups?

You can check the location of the backup folder when you quit Lightroom. If Back up Catalog is set to Every time Lightroom Exits then you will see the Back Up Catalog window (below). Lightroom lists the folder path. You can change it by clicking the Choose button.

How to make Lightroom run faster

If Lightroom is set to save a backup of your Catalog every time you close it down you can imagine how much space the backups take up. The solution is to delete all but that most recent two backups. You don’t need the rest.

You can also free up hard drive space by purging the Camera Raw Cache that Lightroom uses for storing Develop module previews. This is most likely to be useful if you are using a computer with an SSD drive as its main internal hard drive, and the maximum size of the Cache is fairly high.

You can empty the Cache using the Purge Cache button under the File Handling tab in Preferences.

How to make Lightroom run faster

Store your Lightroom Catalog and previews file on your main hard drive

Storing your Lightroom Catalog and previews file on your main hard drive helps Lightroom run faster because this is your system’s fastest hard drive. Lightroom does this by default, so as long as you haven’t changed the location yourself then you don’t have anything to worry about.

If in doubt you can check by going to Catalog Settings (Mac: Lightroom > Catalog Settings, PC: Edit > Catalog Settings). The Catalog name (an .lrcat file) and location are found under the General tab. The previews file (an .lrdata file) is stored in the same location.

How to make Lightroom run faster

1:1 previews are stored in the previews file (.lrdata) and take up a lot of hard drive space. That’s why Lightroom is set by default to discard them after 30 days.

If your previews file is growing too large, you can discard 1:1 previews you no longer need (i.e. you no longer need to zoom into them at 100% in the Library module) by selecting the files in the Library module and going to Library > Previews > Discard 1:1 Previews.

How to make Lightroom run faster

Lightroom doesn’t discard the 1:1 Previews right away in case you use the Undo command. But after a delay it erases them from the previews file. If you have deleted lots of 1:1 previews that can significantly reduce the file’s size.

Update your hardware

So far none of the changes listed require you to update any hardware. But if Lightroom still isn’t running as fast as you would like it then it may be time to consider buying a newer computer. But before you do that, there are some upgrades you can carry out on your current machine to help Lightroom (and other programs) run faster.

Add more memory. RAM is relatively inexpensive so add as much as you can afford. Make sure you buy good quality RAM as inexpensive memory may cause problems with your computer system. Ask at your local computer store or search online for the best type to buy.

If you have a 64 bit operating system you can add as much RAM as you like (within the limits of your computer’s motherboard).

If you have a 32 bit operating system the limit is 4 GB. You can add more RAM if you like but the computer will only be able to utilize around 3.5 GB at the most.

Install a Solid State Drive (SSD) as your main hard drive and make sure your Lightroom Catalog and previews file are stored on it. Solid state drives are much faster than regular hard drives.

Check you have the latest graphics card drivers for your machine. If you have a Mac this should be done automatically, if you use Windows then you should search online to see how to check if you have the latest drivers for your graphics card.

More tips

I hope this advice helps you get Lightroom Classic running at its optimum speed on your computer. If you have any questions or tips of your own then please leave them in the comments.

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Mastering Lightroom Classic: Book Two – The Develop Module ebook
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More great Lightroom Classic tips, tricks and tutorials!


lukas June 20, 2017 - 9:57 am

Hi Andrew,
very good article, lots of useful information.
Actually I was at the beginning of my Lr era creating just standard previews until I watched some training where the instructor suggested for better performance to create 1:1 previews – by better performance here I mean to have pictures instantly rendered when going from one image to another.
However I was not really aware that this works for Library module only. So if my understanding of your article is right, if I spend 99% of my time in Develop module it makes 0 sense to create 1:1 previews, correct?
Thanks again!

Andrew S. Gibson June 20, 2017 - 10:34 am

Hi Lukas, you’re right, it sounds like you have little use for 1:1 previews. 1:1 previews save time when you zoom into images in the Library module. If you don’t zoom in, you can use Standard previews instead. Or you can use Smart Previews, which definitely help the Develop module to run faster.

Katrina Mathers July 26, 2017 - 4:09 pm

Hi Andrew, not the same subject but I was wondering what you recommend for off-site back up options? We back up to two external hard drives but I also want an off-site back up. Thanks…

Andrew S. Gibson July 27, 2017 - 7:54 am

Hi Katrina, if you want to back up photos then the simplest way is to copy them to an external hard drive that you keep off-site, for instance at work or in the house of a relative or friend.

Some photographers use a two drive system for the third back up. To start, you copy your photos to both drives, then keep one off-site (let’s call that drive 2). Then you add new photos to the drive you keep at home (drive 1). Then, next time you go to the off-site location, you can take drive 1 (which has all your photos on it) and swap it with drive 2, which you bring home and update. That way your off-site backup gets updated regularly.

Katrina Mathers July 28, 2017 - 8:29 pm

Thanks Andrew, I was thinking more of a cloud method….

Andrew S. Gibson July 29, 2017 - 2:23 pm

I don’t use them because it takes too long to upload Raw files. This article has a good overview of the most popular cloud backup services.

Katrina Mathers July 29, 2017 - 7:06 pm

Thanks, will take a look.


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