6 Replies Latest reply on Jun 7, 2015 9:41 PM by Rick Gerard

    RAID stripes - and - multiple instance After Effects

    Weldopedia

      RAID: at 50Mbps, each frame of 1080p30 will be about 209KB... if i set my stripe to 1MB will that be detrimental to running multiple instances of After Effects??  If 4.9 frames are contained withing a single stripe, will multiple instances be competing for the same stripe??  Will the other instances simply move to other frames (stripes) and let the first instance finish the other frames in the stripe?

        • 1. Re: RAID stripes - and - multiple instance After Effects
          Mylenium Most Valuable Participant

          None of your questions makes any sense. That's simply not how it works. You can't linearly multiply data rates to calculate I/O performance nor does it do justice to how things work on the AE end, even more so since you work with compressed footage that needs to be decompressed to temporary files for MP rendering. So many failures in your simplistic logic.

           

          Mylenium

          • 2. Re: RAID stripes - and - multiple instance After Effects
            Weldopedia Level 1

              Say we have a RAID, with a 1MB stripe, and four drives, and four instances of after effects and a 50Mbps non-GOP codec. So now, while instance one is accessing the 0-204KiB section of the stripe and instance two, is trying to access the 205-409kiB section of the same stripe, (etc for instances three and four) the other three drives are not doing any work.  But if the stripe was 128KB, all 4 drives would be doing work simultaneously.  Please explain how to properly calculate I/O data rates in order to do justice on how things work on the AE end.

            • 3. Re: RAID stripes - and - multiple instance After Effects
              Rick Gerard Adobe Community Professional & MVP

              That's not really the way AE works. You can network render image sequences but video, especially from compressed sources, doesn't really lend it's self to that kind of processing. You're barking up the wrong tree.

              • 4. Re: RAID stripes - and - multiple instance After Effects
                Weldopedia Level 1

                When did the topic switch to network rendering?

                • 5. Re: RAID stripes - and - multiple instance After Effects
                  Weldopedia Level 1

                  Well, anyways, I tried different sized stripes with no (noticeable) effect.  Just figured that certain lulls in multiprocessing may be attributed to multiple instances competing for the same stripe.

                  • 6. Re: RAID stripes - and - multiple instance After Effects
                    Rick Gerard Adobe Community Professional & MVP

                    Lulls in MP rendering are caused by incompatibility of codecs, effects, and temporal effects in the processing pipeline. MP rendering only works on a narrow range of my projects so most of the time I keep it turned off. If you really want to test MP rendering optimization then render to image sequences instead of codecs. Your wish to render GOP codecs with MP rendering isn't going work well at all because if one frame is rendered at a different speed than another by one of the cores then the sequence is going to get out of order and MP is going to foul things up and either wait or hang while trying to catch up. Writing to disk is not the bottleneck. Stacking up the data for the GOP render is. The only way for the compression for multiple frames to take exactly the same time and work smoothly is for every frame to have the identical calculations for each pixel value and the only way that can happen is if every frame is identical.

                     

                    The reference to Network rendering and image sequences was just to point out that that workflow has been designed and actually works quite well. Trying to write some code to run 4 instances of AE on the same machine and divide up the rendering into something that would efficiently work with GOP formats is experimenting on untested ground.

                     

                    There's a new build of AE coming down the road in a very short time and according to the information released so far the entire rendering engine has been rebuilt. I'd wait for that version to appear before wasting production time trying to squeeze a few extra minutes out of render time. Personally, in my business, I haven't stopped working while AE is rendering since the AME was introduced. Before that I used Steve Ford's excellent products to allow me to continue working on design and animation while BG versions of AE cranked out frames.