4 Replies Latest reply on Jul 31, 2013 5:54 PM by Christos540

    Multi-processing issues

    Christos540

      Hi all,

       

      I'm experiencing MP issues with after effects CS6.

       

      My specs are:

       

      2 x 2.4Ghz 6-Core Xeon

      32GB RAM

      OSX version 10.7.5

       

      I know that countless posts exist detailing this particular issue, however I haven't found any solutions to my specific problem, which I believe

      lies in the size of the job. It's 5.5 minutes of animation. Very few effects are used. Every layer is a vector graphic. There's over 270 layers in this

      project. Collapse transform is on most of the layers - yes I know that CT places more load on the CPU, and no, turning off CT and resizing all my

      comps is not an option. 3.5 Minutes of animation at 512 x 288 was taking over 5 hours to render. I noticed that CPU usage, after around 2 min

      into the render, dropped to 0.5%. I upped the RAM allocation to 4GB per core (3GB was the initial setting), and the rendertime dropped to 1 hour

      which was great.

       

      I have now completed the job, however, I am once again experiencing the same issue with cpu usage dropping to 0.5%, which is strange, as the ram

      usage for each core is still around 2GB, so I am not sure whats going on. Seems that the further along the render gets, the system begins to slow until

      it grinds to a halt. There seems to be very little HDD activity, so virtually no swapping either. I typically purge all memory before hitting the render button,

      as well as leaving on caps lock to prevent the viewer from updating, so I am at a loss as to what's going on. My conclusion is that ae is not handling the

      sheer number of layers that well. I have also noticed that ae keeps overwriting my preferences that I've added -I have 1.5,2,3, and 4GB per core as options

      in the pref file, but not all of them appear in ae. I don't have any SSD drives installed either.

       

      Does anybody have any suggestions? Do I need to just render the project in 2 parts?

       

      Chris

        • 1. Re: Multi-processing issues
          lornaimw Level 1

          I have been experiencing similar issues.

           

          Sorry in advance that I don't know the answer and that I'm likely to be not much help, but my understanding is that if you could have more cores, this would help. Even though you're spreading the work across 6 of them, they still can't all fully undertake it (I think?!)

           

          Other programs like chrome etc can take up space so close all those down too if you haven't already.

           

          These render times do seem extreme considering how good your set up looks to be, so hopefully someone else can help more than I could have!

          • 2. Re: Multi-processing issues
            Christos540 Level 1

            Thanks for responding lornaw,

             

            I've tried with browsers shut down and the problem persists. I'm stumped. I thought I finally had my memory settings sorted, but the last few renders have been abysmal. The project is very much the same all the way through, so it's not like it ever hits a stage that is choc full of effects. It's too bad ae doesn't have a more intelligent memory manager - if it could examine your system specs, comp resolution, effects, no of layers, comp length etc to determine the optimal settings, that would be fantastic. I'm not using an SSD drive but I really don't think that's the problem. It's almost as if I need to stop the render, purge the cache, and restart the render. The cpu's seem to eventually starve from lack of memory. I do the occasional bit of 3D, and I can you tell that 3D apps never seem to have any memory/rendering issues. They take full advantage of multi-core systems. Personally I think that ae just doesn't know how to utilise multi-core systems properly, and falls over when it comes to dealing with massive scenes. No offence to the programmers, but the fact that so many users experience these issues with MP processing turned on, is a testament to poor implementation. Anyways, I've had my ***** for today. Thanks anyway for responding. I'll just have to keep playing with the settings..

             

            Chris

            • 3. Re: Multi-processing issues
              Dave LaRonde Level 6

              Yes, play with your settings: if you're tying to use all 12 cores for AE, it's a bad thing to do.  Start off by leaving about 25% of your processors and RAM for other applications, give yourself about 3 gigs per core, and tweak from there.

               

              And you also might try something even more radical:  don't use multiprocessing when you render.

              • 4. Re: Multi-processing issues
                Christos540 Level 1

                Hi Dave,

                 

                I never try to use all cores. I know better than to try that...:). At the moment I have 3GB reserved for other applications,  2 cpu's set aside for other applications, and 6 actual cpus for after effects to use. I don't have other apps open when I render either. Sometimes I do have MP switched off, but for this project, I wanted to take full advantage of my system. If I had to redo the project, I'd never use collapse transform again. I know it's very convenient to use, but when you have 270+ layers, all with CT on, it really punishes your system. I think if i used hi res tiffs instead of vectors, the system would fly. I've noticed the difference in responsiveness, with CT off. Thanks for replying anyway Dave. Seems I'll have to optimise my scene. I'll report back my findings.

                 

                Chris