Since Lightroom is utterly unusable without rendering Previews, I am now stuck with generating 2000 Previews before being able to start actual work.

Now the issue is that during the time the Previews render I can't seriously do anything else as the whole computer (pretty powerful) is bogged down by the task.

Ideally I would be able to start editing while Lightroom is calculating previews in the background. But that's obviously not the case—while other apps at least manage to get some CPU allotted to them, Lightroom itself is just unusable.

So I was wondering if there is a way to limit Preview-Rendering to one CPU core? That way I can at least use Photoshop in the meanwhile. Or do something at least somewhat useful.

Any ideas?

PS: I am Running Lightroom CC on Windows 7 x64

  • \$\begingroup\$ Cull using Photo Mechanic and you wont have to generate previews for 2,000 images. And culling full size images in PM is a treat. Once you do need to generate previews, take a coffee break and come back :) \$\endgroup\$
    – dpollitt
    May 1, 2015 at 14:15
  • \$\begingroup\$ Yes that's the workflow I usually use. But in this case I really need to (mostly batch) 2000 pictures :( \$\endgroup\$
    – Tigraine
    May 1, 2015 at 15:08

1 Answer 1


In windows task manager, you can lower the priority class of the Lightroom process. That will help other processes to get some more CPU time, and quite frankly i think Adobe should have implemented those long running tasks with idle priority anyway, so working interactively could continue as normal.

You also can fiddle with CPU affinity of the Lightroom process, ie. restrict it to certain CPUs.


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