Lightroom painfully slow

It takes forever to complete a command

Specifically, what command?

it is extremely laggy when trying to use any adjustment layers

Do you mean "adjustment brushes"? Yes, laggy adjustment brush performance is a known problem, made worse by 4K or larger monitors and/or very large image sizes. How big are your images (in megapixels or pixels)? Is your monitor 4K or larger?

Hi there,

We are sorry about the experience with Lightroom Classic. Would you mind sharing the version of Lightroom Classic you are using on both machines and the operating system versions on both?

You can try the steps mentioned below on one of the machines and test how things go? If it helps, you can perform the steps on the other computer as well.

1. Go to Preferences > Performance and increase the Camera Raw Cache size to 10.0GB or more.
2. On the same tab, check the option to Use Smart Previews instead of Original for image editing and uncheck the option to Generate Previews in Parallel.
3. On the Performance tab itself, select off from the drop down for Use Graphic Processor
4. Go to the General tab and check the box to Replace Embedded previews by standard previews during idle time.

Once you have made the above-mentioned changes, quit and relaunch Lightroom Classic prior to testing the application.

Regards,

Nikunj