In response to customer requests, Adobe have compiled a list of the most popular Lightroom performance tips and tricks and posted it as a TechNote.
There are some very good hints in there. One section that’s causing some confusion is “avoid corrections you don’t need”. The idea behind it is simple – the more adjustments you apply to each photo, the longer Lightroom will take to calculate them all. So, for example, if a photo doesn’t need lens corrections, you’ll speed Lightroom up by turning them off.
It especially applies to local adjustments – brushes and graduated filters – which are particularly processor intensive. Let’s consider an example. If you’re brushing a local exposure adjustment to lighten some shadows, and you’re going to apply local noise reduction to the same area, include both sliders in the same brush rather than creating two separate brush strokes. But at the same time, ensure other brush sliders are set to 0 if they’re not needed, for example, there’s no need for the Highlights adjustment in this scenario.