7 Replies Latest reply on Jun 24, 2015 11:23 AM by bob frost

    Lightroom 6 Render Very Slow


      I have recently upgraded to Lightroom 6 and have found that rendering previews takes about twice as long as Lightroom 5. I have an iMac with 5K Retina display and Lightroom says the GPU is enabled in settings. I'm just wondering if anyone else is having the same issue, because I thought this version of Lightroom was suppose to be faster.

        • 1. Re: Lightroom 6 Render Very Slow
          petehz Level 1

          Not sure it's the same issue but also finding LR6 very very slow and also seem to be getting a lot of 'not responding' messages.  Seems to take and age to do anything.  Had some speed issues with LR5 but nothing nearly as bad as LR6

          • 2. Re: Lightroom 6 Render Very Slow
            Wolf Eilers Level 4

            Lr 6/CC slow? Try turning off GPU acceleration. Magic!


            Edit: GPU acceleration should benefit 5K displays. I use Windows so should not comment further on Mac usage.

            1 person found this helpful
            • 3. Re: Lightroom 6 Render Very Slow
              petehz Level 1

              Just checked and it's already off, well disabled due to errors.  My problems seem to be more related to the new people module e.g amending the names of tagged faces is taking forever and my whole screen turns black and it takes about 10 secs to complete each amend.  May be an idea to just not use this new functionality I guess!

              • 4. Re: Lightroom 6 Render Very Slow
                Arpit Kapoor Adobe Employee

                Hi kylegherman,


                Would suggest you to upgrade your graphic card drivers and then check the same.


                ~ Arpit

                • 5. Re: Lightroom 6 Render Very Slow
                  bob frost Level 3



                  I've got the same problem with LR cc 2015.1. It is much, much slower at rendering 1:1 images than LR 5.7.1.


                  In LR5 a 36MP D800 image takes about 5 secs to render. In LR CC 2015.1 it takes between 8 and 20 secs. I've done various expts, with and without gpu on, without face recog on, without sync on, without internet on, without virus checking on, without ...... But it makes no difference; if it is feeling in a good mood, LR CC 2015 can render the 1:1s in 8 secs, but it is often 10-12secs, and with time it gets slower.


                  Last night I did another check and it was about 9 secs before I went to bed, and  15 secs this morning. Simply stopping rendering and restarting it makes no difference - if it was 15 secs before I stop it, it is 15 secs afterwards. The only way to make it go back to 8 secs is to close and restart LR. Nothing I can think of makes it go as fast as LR5.


                  I've even exported my 90K images catalog and created all new standard previews and .dat files. Still no difference.


                  I have a fast desktop with ssds and hdds and 32GB ram (Win8.1)


                  So what have you done in LR CC 2015 that makes rendering take so long.


                  Bob Frost

                  • 6. Re: Lightroom 6 Render Very Slow
                    bob frost Level 3

                    I've looked further at the difference in rendering 1:1 previews of D800 files in LR5.7.1 and LR CC 2015.1 on different catalogs and preview sets, but with the same acrcache fully populated.


                    I recorded the processing of one file in both versions of the program using Windows Process Monitor (Sysinternals).


                    What I noticed when comparing the two is that LRCC spent 4 whole seconds, in two 2sec waits, doing something in the SLcache. LR5 did not do this, and therefore was 4 secs faster.


                    I have read of people being advised to delete the contents of this cache to solve other problems, so I deleted its contents - C:\Program Files (x86)\Common\Adobe\SLcache


                    Now it is 4 seconds faster!! and apart from a couple of refs to that cache, LR CC doesn't seem to use it or at least doesn't 'waste' any time in it.


                    Not sure what the SLcache is for. Does anyone know?


                    It might be worth trying this on all instances of slow processing in LR CC 2015.1


                    "If at first you don't succeed, try, try again" as my old granny used to say!!!!!


                    Bob Frost

                    • 7. Re: Lightroom 6 Render Very Slow
                      bob frost Level 3

                      After running for an hour creating 1:1 previews, LR CC 2014.1 is now spending 2 secs trying to close the SLcache again! What is wrong with this program?


                      Bob Frost