While I can’t say this Adobe Lightroom cache optimization tip did all that much to increase speed for me, I recognize the benefits could be workflow dependent. By default (at least for me), Adobe Lightroom’s RAW cache is configured for 1GB. But, if you have the hard drive space available, why not increase this cache setting? And for an even greater speed boost, if you have a solid state drive (SSD), make sure that is where your cache is located.
Here’s what Adobe has to say.
Every time you view or edit raw images in the Develop module, Lightroom generates up-to-date, high-quality previews. It uses the original image data as its foundation, and then updates the preview for any processing or adjustments that have been applied. The process is a little faster if the original image data is in the Camera Raw cache. Lightroom checks the cache for the original image data and can skip early stage processing if the image data is cached. (Adobe Lightroom – Optimize performance)
To change the cache value (and location), go to Preferences (Edit menu on Windows / Lightroom menu on Mac), then click on the File Handling tab. Near the bottom there is a section called Camera Raw Cache Settings.
Bump up the Maximum Size to whatever value your free drive space can reasonably handle. And change the Location for the cache to an SSD (if you have one available with enough free space). On my MacBook Air, I bumped the cache up to 10GB, but if free space allows, you might want to consider 20GB, 50GB, or more, especially if you have a lot of photos (tens or hundreds of thousands) in your catalog.