12 Replies Latest reply on Jun 19, 2015 2:05 PM by ManiacJoe

    Why is Lightroom 6 extremely slow when building 1:1 previews?

    Robert Stoner

      On my MacBook Air, Lightroom 6 is extremely slow building 1:1 or smart previews. Overall, Lightroom 6 is slower that Lightroom 5 when processing in the Develop Module, even after 1:1 previews are built. Catalog has 92,000 images which didn't seem to be a problem with Lightroom 5. What's up?

        • 1. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
          Jao vdL Adobe Community Professional & MVP

          Lots of people have success speeding up the program by turning OFF GPU acceleration in the performance tab in preferences. Perhaps try that. The GPU in a Mac Book Air is likely not the most speedy and it might not even support GPU acceleration but it doesn't hurt to try. For me with GPU acceleration turned off on a recent retina Mac Book Pro it is as fast as Lightroom 5.

          • 2. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
            Robert Stoner Level 1

            Thanks. Processes inside the Develop module seem to be snappier. Moving through the film strip, while 1:1 images load is significantly faster. I will test building 1:1 previews soon.

            • 3. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
              bob frost Level 3

              I'm using a very fast desktop (Win8.1) with multiple ssds and hdds and 32GB ram. I was just making some 1;1 previews of D800 files with LR6 CC 2015 and found that it was taking about 18 secs per image. So I closed LR6 and reopened LR5.7.1 with separate catalog and previews (but the same images) and found that LR5 took 4-5 secs per image, which is about what I remembered. So I closed LR5, reopened LR CC 2015 and ran the build 1;1 previews again on similar files. This time it was only taking 10 secs per image. But even that is twice as long as LR5 takes. Why??? And why was it taking 20 secs per image when I first timed it (after it had been building previews for an hour or so).

               

              Something strange is going on with preview building in the latest version of LR.

               

              Turning graphics card use on and off had no effect, nor had turning Internet access on and off. Sync, address lookup, and face detection are all paused.

               

              Bob frost

              • 4. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                Robert Stoner Level 1

                I failed to mention that shoot with the Nikon D4s. Sync, lookup and face detection are all paused. I am not converting to DNG. My normal shoots average between 1,700 to 2,000 RAW images. I normally build smart previews on import from the camera. I am using XQD card. With Lightroom 5, it took about an hour and a half for the import. With Lightroom 6, I let it run and it took 16 hours.

                • 5. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                  bob frost Level 3

                  After 9 hrs building D800 1:1 previews, the rate has dropped from about 10 secs per image to 18 secs per image. This seems to have been a gradual decline through the night as I can see from the timestamps on the acrcache .dat files. As I said previously, this compares with 4-5 secs per image in LR 5.7.1 with the original catalog and previews and image files.

                   

                  Why so slow in LR6 and why the gradual slowdown?

                   

                  bob frost

                  • 6. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                    bob frost Level 3

                    More info. Using Sysinternals Process Monitor, all the extra time building 1:1 previews in LR CC 2015 seems to be taken up with reading/writing to temp files and the previews.db-journal. That seems to double or quadruple the time taken to build the D800 preview.

                     

                    Bob Frost

                    • 7. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                      bob frost Level 3

                      Even stranger! If I create a 1:1 preview in Library by simply clicking on the Loupe view, it only takes about 5 secs (same as LR5). It is even quicker in Develop. Yet by using Library/Build All Previews it takes 10-20 secs!!

                      Something wrong somewhere.

                       

                      Bob frost

                      • 8. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                        willanywork Level 1

                        Similar problem.  It's not just previews, it is DNG creation too. What takes 2 hours on 5.7.1 (on a Mac) now take 5 hours in LR CC 2015.1 on the same Mac.  I was hoping they would find the problem and fix it in the .1 release but they did not.

                        • 9. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                          trshaner Adobe Community Professional & MVP

                          Bob check your Catalog Settings in LR5 and LRCC. Are they the same? On Windows 7 with LRCC and Canon 5D MKII 21Mp raw image files I'm seeing about 5 sec 1:1 Preview building for both 1:1 Zoom and 'Build 1:1 Previews' with multiple images. I ran a test on 60 image files, which took about 5 min. I can't say what it might be after an hour. Do you see the slower 1:1 Preview building (10 sec. vs 5 sec. in LR5) right away?

                          • 10. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                            bob frost Level 3

                            Yes, they are the same - 2048 and High. Just checked again. With Build All 1;1 previews, it starts at 10 secs and slowly gets longer with LR CC 2015. After a reboot it is back to 10 secs. I keep clearing the acrcache before each test, so as to standardize things. The catalog and previews are on a very fast SSD. The acrcache is on another ssd, while the system is on a 3rd ssd. Images on a big internal HDD. I'm fast running out of things to try!!

                             

                            Bob Frost

                            • 11. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                              trshaner Adobe Community Professional & MVP

                              What processor are you using and what does the utilization look like the utilization in Performance monitor?

                               

                              bob frost wrote:

                              I keep clearing the acrcache before each test, so as to standardize things.

                              Why? That will slow 1:1 Preview building because you have two processes running in parallel: 1:1 Preview and ACR Cache Building. That might explain why it starts out at 10 sec. and then gets slower as the ACR Cache building starts chugging in the background. I know viewing an image in the Develop module will cause the ACR Cache file to be built after importing images or purging the ACR Cache and I would think 1:1 Preview Building will trigger it as well. Lightroom's internal task monitor may then "throttle" the 1:1 Preview Building since it detects two processes running at the same time. We know LR controls processor usage since it's impossible to get more than ~50% utilization. This is all guess-work as Adobe has not published anything on the "inner-workings" of the ACR Cache.

                               

                              As a test you can create a folder with 100 or more images in it, purge the ACR Cache, Discard 1:1 Previews, and Build 1:1 Previews. Record the time to complete. Rerun the same test, but do NOT purge the ACR Cache.

                              • 12. Re: Why is Lightroom 6 extremely slow when building 1:1 previews?
                                ManiacJoe Adobe Community Professional

                                DNG is a different problem, should be its own thread.

                                 

                                Raw-to-DNG conversions in LR 6.x are handled differently from LR 5.x. The resulting side effect is noticeably slower DNG conversions in LR 6/CC.