Lightroom Performance Tips
Having suffered with computer problems all weekend, I'm typing this on an old and slow backup laptop. As such, it seems like a perfect occasion to review some tips for improving performance in Lightroom.
Photoshop users often have more than one image open at a time, all of which take memory. On the other hand, Lightroom typically has to fully render just a single image at a time. The small images in the Library module don't cause much of an impact. It's the image you are working on in the Develop module that takes up the lion's share of what Lightroom consumes.
But while we're talking about Photoshop, let's start with it. If you run both Adobe applications it should be obvious that running both at the same time takes more resources that does either separately. If you do run both, start by doing some optimization on Photoshop. I haven't written extensively on Photoshop performance tuning since the days of Photoshop CS2 but much of this is still valid. Adobe has a good tech note on optimizing Photoshop that has been updated through CS6. Most relevant to the topic at hand of Lightroom performance is to limit the amount of memory that Photoshop uses so there's some available for Lightroom.
Once you get your Photoshop configuration properly tuned, it's time to come back to looking at Lightroom. Adobe has a couple of good tech notes on Lightroom performance as well. The top item on their list is making sure you have the latest version installed. Within reason, I'd agree with this. But with the beta of Lightroom 5 out there, be advised that the beta version of most anything will take more than the latest stable release of the prior version. Generally all the beta slowdowns will be resolved by the time Lightroom 5 ships, but for now those with limited computer power would do well to stick with the latest release of Lightroom 4.
Make sure to keep your video driver updated too. Sometimes the slowdown may not be Lightroom itself but rather the mere act of attempting to render everything to your monitor. Keep the image zoom set to an even multiple too. Fitting an image to your screen size may make it as big as possible but may also require more work to render if the magnification is an odd ratio.
Within Lightroom, everything you do is non-destructive. By that I mean that none of your underlying image pixels are ever actually changed in any way. An image merely looks like it's been changed since you are always looking at it with the benefit of your changes applied in real time to the preview image you see. The same thing happens when you print or export an image in any way. While this is indeed good for the safety and integrity of your original images, it does impose a certain performance cost to render what you see. Open an image and whatever changes you have previously made must get applied so you can see their effect. Change one of those edits and the Develop preview must get recalculated accordingly.
The more changes you have made the more work will be required to recalculate them. Spot removal and localized edits can start to have a noticeable impact on performance if you have too many. There are no hard and fast rules, but Adobe says they aren't designed for "hundreds to thousands" of edits. When you start getting up in this territory they recommend you consider using Photoshop or another pixel based editing program. Try to combine edits when possible too when applying localized corrections to cut down on brush strokes.
Adobe also recommends making changes in a certain order if possible. This may not always be practical given that you'll generally want to tackle the biggest problems first regardless of what they may be, but when possible here's the sequence Adobe recommends. First deal with any spot healing needed to get rid of dust spots and the like. Then apply any needed geometry corrections, either manually or via available lens profiles. Next tackle global non-detail corrections such as Exposure and White Balance. Then move on to address any needs for local corrections such as Gradient Filter application or Adjustment Brush strokes. Lastly, apply and needed detail corrections such as Noise Reduction and Sharpening. And don't apply any changes you don't need to.
We can all use some good performance tips on occasion. Sometimes of course the only answer is to upgrade or fix your computer if the one you are using or forced to use is underpowered. If you've been putting off an upgrade or looking for a good excuse for one, this may well be it.My new laptop is ordered and should be on its way soon.