12 Replies Latest reply: Jul 17, 2009 10:08 AM by Fried Green Pixel RSS

    Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?

    Fried Green Pixel

      For some reason Lightroom 2.4 is taking an enormous amount of time to render thumbnail previews and in spite of having my thumbnail cache set to 50 GB, it still re-renders the thumbnails every single time I use the scroll bar.

       

      Every other aspect of Lightroom performs just fine on my machine.  But the library is so slow that it is unusable.  Every time I touch the scroll bar I can see a somewhat darker preview of the thumbnails and then as soon as I stop scrolling, the CPU shoots up to 100% utilization and I watch as the thumbnails brighten and adjust one by one.  30 to 45 seconds later I can click on the thumbnails and navigate around just fine.  Performance is great in fact until I touch the scroll bar again.

       

      The basic question is this.  Why does Lightroom refuse to cache my thumbnails?  And why does it take soooo long to render them when Vista's explorer can render hundreds of thumbnails off even a flash card in seconds?  Even if thumbnail rendering was slow it would be fine if Lightroom would only cache them for me so it doesn't have to redo it every time I scroll back and forth.  Shouldn't there be an option to render thumbnails on import as well as 1:1 previews?

       

      I am running Vista 64 bit with 4GB of RAM with a Gforce 7600GT graphics card.  My library has about 18,000 images in it.  But I've also tried with a brand new small catalog.  I'm shooting and processing Nikon D300 RAW files.

       

      I've done all the standard performance tweaks that everyone talks about:

       

      1.  I render 1:1 previews and never expire them.

      2.  I have tried all the various nvidia card tweaks.

      3.  I've updated to the latest and greatest nvidia drivers.

      4.  I have my catalog on a separate drive from my images, and my thumbnail cache on yet a 3rd drive.

      5.  My machine has plenty of RAM, and in fact Lightroom is only using 1.5GB leaving me with well over 1GB remaining.

      6.  My machine is not swapping at all.

       

      I've been reading and reading for the past 24 hours about this issue but have yet to come up with an answer to it.  I did find this old thread from over a year ago that describes the EXACT same problem I am experiencing except his problem was with version 2.3:  http://forums.adobe.com/message/1395391#1395391

       

      Does anyone have ANY idea what can be causing this?  As is, I can't use Lightroom under these conditions.

       

      Thanks!

        • 1. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
          DdeGannes CommunityMVP

          Quote "4. I have my catalog on a seperate drive from my images, and my thumbnail cache on yet a third drive."

           

          Could you expand on this. It would be best, provided there is sufficient room, to have the catalog, previews and the cache on main HDD with the program file.

          It would be ok to have your images on another drive preferably an internal HDD but an exernal drive is also ok.

           

          Do not consider a partitioned  drive to be another drive its still one HDD only seperating files so there is no performance benefit.

           

          Better to keep the external drives for  backup .

          • 2. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
            Fried Green Pixel Community Member

            DdeGannes,

             

            Thank you for your reply, but I am not sure why placing the catalog, previews and cache all on the same drive would improve performance.  Also, when I say separate drive I mean separate physical internal drive.  I have 4 physical internal drives on my machine.

             

            I have tried placing the catalogs, cache, previews on the same drive but it didn't help.  This is how Lightroom was originally setup until I moved them all to separate drives to try to increase performance.  The problem is not disk IO bound, but rather CPU bound.  Every time I scroll, the thumbnails are being completely redrawn from scratch even if I have already viewed them before.  And my CPU spikes to 100% while the thumbnails are rendered and then drops back down to idle afterwards.  But the process takes over 30 seconds to render the 15 or so thumbnails in the scroll pane.

            • 3. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
              DdeGannes CommunityMVP

              What you have done make sense, but it was not specific in your original post. What I was suggesting was if you had two internal drives. I just wanted to make the point that having the catalog, previews and cache on external drives would not be the way to maximize performance. I have no idea why you are experiencing the slow performance.

               

              Just one other point the Library module uses the previews but when you are in Develop module the raw files are used to render the display. Its more efficient to use the Library to browse.

              • 4. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                kwdaves-WfiRTh Community Member

                Fried (or Mr./Ms. Pixel),

                 

                For whatever reason, that was the way Lightroom was designed. When you bring a thumbnail on screen in grid view or on the film strip, Lightroom applies the develop settings and creates the thumbnail badges. The process isn't over until the "..." goes away.  With Lr 2.x it takes longer the first time it does this for each screen full of thumbnails, about 30 seconds on my zippy Core2 Quad. Thereafter it takes much less time for the "..." to disappear for those thumbnails, 1-2 seconds for me.

                 

                Something I haven't noticed before Lr 2.4 is that now and the "..." will freeze for a few thumbnails and won't go away until you scroll them off screen and then back on.

                 

                This has been discussed in innumerable threads from Lightroom's beginning.

                • 5. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                  Fried Green Pixel Community Member

                  So I spent all evening experimenting with different things in Lightroom to try and improve performance and found 1 solution that worked.  Although I'm not sure why.

                   

                  I understand that a design decision was made to render thumbs on the fly.  Fine.  But what I couldn't understand was why it took so incredibly long.  I mean the process was literally locking up my entire machine every time I touched the scroll bar.

                   

                  The ONLY thing I could get to clear up the problem was to select the top level folder in my catalog, and export the entire catalog as a new catalog.  For export I did NOT choose to export the image files or the previews since I only wanted to keep my database (image adjustments, keywords, etc).

                   

                  Upon opening this newly created catalog, of course everything was slow because there are no previews for anything.  Fine.  So I chose to render standard sized previews for a couple of the folders in the catalog (about 150 photos each).  And then lightroom became extremely fast for browsing and scrolling through thumbnails on those particular folders.

                   

                  What I can't undertand is why rendering standard sized previews on my old catalog (same photos, same folder) does not improve performance, yet doing it for the new catalog which should be an exact copy DOES improve performance.

                   

                  The only thing I can think of is that my original catalog must have either been corrupt or there may be some upper limit on how many previews Lightroom can handle gracefully?  Since I had standard previews for my entire catalog before.

                   

                  I'm going to try and render standard sized previews on my entire new catalog tonight and see if the performance remains snappy.  But something is definitely not right here.

                  • 6. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                    J McWilliams Community Member

                    It sounds like you are on the right track. Sometimes the Previews folder becomes corrupt. What I might suggest is changing the name of either the .lrcat or the Previews folder' either one will force build a new Previews for the whole thing. If, after checking out a couple of folders in the old .lrcat but new Previews, things aren't better, you can just change the name back, and you'll be accessing the "old" Previews folder. But I bet you'll see an improvement on everything.

                    • 7. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                      Fried Green Pixel Community Member

                      Thank you for the response John, I will be trying this as soon as I get home this evening and will post back with results.  You mention that sometimes the previews folder gets corrupted.  Is this a common issue?  I mean how often can one expect to get a corrupt previews folder?

                      • 8. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                        J McWilliams Community Member

                        No, I wouldn't say it's common, but as usually folks post here to solve a problem, it - slow performance- shows up every few days- but it isn't always a corrupt Previews file, to be sure. I wouldn't expect it to happen again.

                        • 9. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                          Fried Green Pixel Community Member

                          So just an update.  Last night I rendered all the standard sized previews for the brand new catalog I created (18,500 images).  And this morning the catalog view is once again flying!  I can easily skim through my photos now and the '...' on the thumbs only flashes for a split second.

                           

                          So it would seem as though something in my old catalog was indeed corrupt, whether it be the previews file or something else within the catalog.  But the fix was to export the entire catalog as a new lightroom catalog withough checking "export photos" or "export previews".  This only makes a copy of your catalog database to preserve your edits, etc.  And then open the new catalog and render standard previews.

                           

                          Hopefully this helps someone else that runs into this issue.

                          • 10. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                            J McWilliams Community Member

                            Glad it's fixed. I am pretty sure it was the part of the new catalog that brought you a new Previews folder that fixed it, but your method covers that base nicely, with a bit more time and work.

                            • 11. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                              Fried Green Pixel Community Member

                              Out of curiousity I think I'll test that theory tonight and post back afterwards. 

                              • 12. Re: Why is Lightroom 2.4 Thumbnail Rendering SLOOOOOOOOW...?
                                Fried Green Pixel Community Member

                                So after testing this last night it appears it was not my previews folder that was corrupt afterall, but rather something in the catalog itself.

                                 

                                I went back to my old catalog after completely removing the old previews folder.  Upon starting Lightroom I saw it create a new previews folder as you would expect.  I built the standard sized previews for the old catalog again and the speed remained horrible as it once was, taking about 10 seconds to render each and every thumbnail before the "..." would go away, all the while my CPU sitting at 100% and freezing up Lightroom.

                                 

                                Same problem as before.  Switching back to the new catalog that was created from exporting the old catalog showed an immediate performance gain, rendering a page full of thumbs in about a second.