Things will run much faster with those files right on your main internal hard drive.Ģ) You have less than 16GB of RAM (that’s not the minimum it takes for Lightroom to run, but it’s what Adobe recommends).ģ) Your internal hard drive is slow. It’s fine for photos to be stored on an external hard drive (in fact, I recommend it), but not your Lightroom Catalog file or previews files. Well, I guess it should read, “one or MORE of these seven reasons:ġ) Your Lightroom Catalog (and preview files) are NOT on your computer (you’ve stored them on an external hard drive).