4 Replies Latest reply on Sep 29, 2016 8:36 PM by Roei Tzoref

    Why is preview rendering so slow?

    aspen1135

      Sorry if this is a simple question but why is my preview rendering so slow? I have a pretty kickass setup: an i7 @ 3.9ghz, 8gb ram, HSSD, and an gtx 760 1gb and a audio interface to handle the audio. I just started using after effects and have been experimenting with some 30 minute TV episodes. After enabling Twixtor for some slowmo effects (along with the pre-reqs it needs like time remapping & frame blending) my computer starts to stutter frames and slow down audio upon playback. But then after playback of an already played segment (with it stuttering, etc), it'll then play smoothly again. I understand that Green means 'played by GPU', yellow means 'needs to be rendered' and red meaning 'has been rendered' but if it's all in the green, and I have a really fast CPU & GPU and relatively low amount of FX, why is it struggling to render the preview in real time?

       

      I am on windows x64 bit and am using AE CC 2015

        • 1. Re: Why is preview rendering so slow?
          Roei Tzoref Adobe Community Professional
          experimenting with some 30 minute TV episodes.

          are you saying you have 30 minutes video in your Ae Timeline?

          After enabling Twixtor for some slowmo effects (along with the pre-reqs it needs like time remapping & frame blending) my computer starts to stutter frames and slow down audio upon playback.

          very intensive calculations. what's the resolution? what is the video format (codec - see the project window at the top left what does it say about your video) how long are these effects affecting your layers? how many layers? what else have you got there? a screenshot of your full Ae interface would be nice. try working in half res, or view one segment at a time.

           

          I understand that Green means 'played by GPU', yellow means 'needs to be rendered' and red meaning 'has been rendered' but if it's all in the green, and I have a really fast CPU & GPU and relatively low amount of FX, why is it struggling to render the preview in real time?

           

          Green means it's cached in RAM. no relevance to the GPU. Yellow means... wait.. there's yellow? Red? are you in Premiere?  the only colors you are supposed to see are Green and Blue.

           

          try reading this see if you can figure it out yourself:

          Improve performance in After Effects

           

          and screenshots

          • 2. Re: Why is preview rendering so slow?
            Dave LaRonde Level 6

            aspen1135 wrote:

            I have a pretty kickass setup: an i7 @ 3.9ghz, 8gb ram, HSSD, and an gtx 760 1gb and a audio interface to handle the audio.

             

            Actually, you're a little light on memory.  16 GB RAM is pretty much the standard these days.

            • 3. Re: Why is preview rendering so slow?
              aspen1135 Level 1

              Aha. I probably got it from a video when I was learning premiere pro. Thanks for clearing that up. The TV series I was testing/experimenting with was 720P but the real project video I am currently working on is a much lower resolution and time scale. It seems as though when I just had 30+ minutes on the composition it made my computer very unhappy.

              • 4. Re: Why is preview rendering so slow?
                Roei Tzoref Adobe Community Professional

                although the limit of any composition is 3 hours, you should work just on the part's you need to and if you have any playback issues we can help you solve them, but we need to know what the exactly you got there. you probably don't need a composition longer then a few seconds for different parts of a TV Spot. once your timeline is in a more reasonable duration, you will see exactly where it struggles and can address that.