4 Replies Latest reply on Jan 26, 2013 10:32 AM by featheredtar

    CS6 - After generating 3-7 RAM previews w/multiprocessing, MP stops working

    featheredtar Level 1

      When I start AE (CS6) 10.0.2 (Win7, x64), previewing a 10-15 second scene with multiprocessing works fine and is very fast. After making 3-7 different RAM previews by pressing numpad 0, AE will no longer generate these previews, and instead will either say that it's preparing to do so, or stop at having rendered "2 frames out of x". I can see that it has stopped working because in the Task Manager, the different instances of AE will not be consuming more RAM to prepare for frame renders. AE and my system will still work fine, and I can still view the RAM previews that I made beforehand, but to get MP to work flawlessly again, I need to restart the program.

       

      I'm using an 8 core Xeon processor @ 2.6 ghz, with hyperthreading enabled, and with 32 GB of RAM for this processor. I've read that decreasing the amount of available cores can help with AE multiprocessing. I've tried that, as well as playing with the amount of RAM that each core gets, and it still will inevitably hang. I've also read that problems like this can be due to hard drive bottlenecks. When I look at Windows Resource Monitor, this isn't a problem at all. I'm using AE to make compositions with JPEG time lapse sequences that can be anywhere from 2,000x2,000 px to 25,000x20,000 px large, and often with multiple JPEG time lapses together. It's for this project in case you're curious.

       

      I spent a lot of money on this system, and plan to add another 8 core Xeon processor along with another 32 GB of RAM just to get faster renders (it's a dual socket ASUS board). Hopefully there's a fix for this flakey multiprocessing situation, or will be an update in the future. I think turning MP off does work, but it seems needless to do something 8 times as slow, or to have to always restart the program just to use a basic feature.:

       

      EDIT: I should also say that rendering final compositions with multiprocessing ususally works. For 2-5 minute projects, it almost always works. Rendering 30-70 minute compositions sometimes works. Sometimes it crashes during these longer ones, and I have to try repeatedly, and eventually it'll work. Sometimes doing things like emptying the Media Cache works.

        • 1. Re: CS6 - After generating 3-7 RAM previews w/multiprocessing, MP stops working
          Dave LaRonde Level 6

          I'll assume the image sequences are interpreted at the correct frame rate for this project.

           

          If you're mixing image sequences of different dimensions in a single AE comp, try working with NO multiprocessing to see what happens.

           

          Personally, I'd render one sequence per comp, render them out in AE, then finish up in a video editing application.

          • 2. Re: CS6 - After generating 3-7 RAM previews w/multiprocessing, MP stops working
            BenjaminMarkus Level 4

            As Dave said, I'd render one image sequence per comp and assemble them later in an NLE like Premiere Pro. 

             

            But, if you have to render really long 30-70 minute compositions out of AE, I would render to a PNG image sequence.  PNGs are smaller than TIFFs and the quality is excellent.  This way if you're render gets stopped due to a crash you can start it again from where you left off instead of having to re-render from the beginning.  All you have to do is remember to check the Skip existing files box in the Render Settings window, which will also allow you to render using multiple machines:

            Skip_Existing_Files.png

            You will of course have to re-render the final image sequence to a contained movie file, but pre-rendering the whole thing to an image sequence first should make the final render fast and painless.

            1 person found this helpful
            • 3. Re: CS6 - After generating 3-7 RAM previews w/multiprocessing, MP stops working
              featheredtar Level 1

              The sequences are @ 20 fps in 30 fps comps. But I also routinely time remap the sequences, so the frame rate fluctuates.

               

              Working without multiprocessing does work consistently, but then previewing is obviously comparatively slow.

               

              That's a good idea. It seems that AE is made for smaller sequences.

              • 4. Re: CS6 - After generating 3-7 RAM previews w/multiprocessing, MP stops working
                featheredtar Level 1

                Good call. I have done that for previous projects - it works great.

                 

                Great idea re. rendering individual frames! - I hadn't thought of that.

                 

                I've tried doing a network render, but I have found that it is actually slower than using just my 8 core Xeon machine. It doesn't seem like AE is smart enough to get both computers to work out their long-term schedules for which frames to render far enough in advance. I think that the Xeon machine will load footage into the RAM to get ready to render a frame, which the second computer ends up rendering instead-thus negating that work. An alternative to this overlapping of effort could be giving the Xeon machine 3/4 of a project, and giving the second computer the last quarter, so that they wouldn't have any chance to render frames that end up being rendered by the other computer. But maybe I'm doing something wrong.

                 

                But rendering the final sequences works great, and the fact that it crashes on the longer sequences seems more to be a symptom of my workflow rather than anything else. The main thing I want to fix is this pesky multiprocessing RAM preview problem that makes me have to restart the program often.