7 Replies Latest reply: Dec 15, 2013 9:49 PM by Suntower RSS

    Yes: Another Noob Speed Rendering Question

    Suntower Community Member

      Hi,

       

      I recently put together another 'budget' PC for my work... which is mainly web development. I do some Premiere video. I -sometimes- use AE, but frankly I only know enough to borrow from other's projects.

       

      Haswell 4770k, 16GB DDR3, 240GB SSD. I'm using the built-in graphics. This is working -fine- for my Premiere needs. Renders are peppy.

       

      What surprises me is that AE is such a rendering -dog-. Specifically, I downloaded this Ocean project: http://vimeo.com/5384704

       

      The project renders in 5 minutes. But then I made what I -thought- were a couple very minor tweaks... ie. I automated the transparency of a couple of the layers... and then render time ballooned to 1hr.

       

      So, I activated Multi-Processing, moved the caches to the SSD and the effects? Negligible. I just found out about the Background Renderer which I'm going to try tomorrow, but I was also wondering if there are any other things I should try?

       

      1. I was led to believe that the GPU is not really a major factor in AE rendering times. Correct?

       

      2. AE says it's using 14.7GB cache during rendering. Would investing in more RAM chips -significantly- help?

       

      3. Is there something about using keyframes with opacity that is a real CPU hog? Or are keyframes in -general- the reason for the huge rendering time increase? I knew certain effects were more intense than others, but this was a surprise.

       

      Any other suggestions? I'm sure this has been asked a zillion times but I wanted to cover all the bases since the increase in rendering time caught me off-guard.

       

      TIA.

       

      ---JC

        • 1. Re: Yes: Another Noob Speed Rendering Question
          Mylenium ACP/MVPs

          GPU doesn't matter for final rendering unless you use a raytrace 3D layer. The disk caches and RAM caching are two unrelated things and the disk caches don't matter much for final rendering because most render settings will override cached data if e.g. it is at only half res or motionblur wasn't used for previewing to save performance. The rest is unclear since we don't know what changes you actualyl made. Keyframe evaluation should be negligible, but naturally using transparencies may require additional blending operations to happen that cost render time.

           

          Mylenium

          • 2. Re: Yes: Another Noob Speed Rendering Question
            Dave LaRonde Community Member

            I took a quick look-see at that tutorial, and I noticed that Aharon Rabbinowitz was working in 16x9.... but at 640x360.  Did you do your stuff in HD, with about 10 times more pixels to deal with?  AE's thinking time would go up by quite a bit.

            • 3. Re: Yes: Another Noob Speed Rendering Question
              Suntower Community Member

              Hi,

               

              Sorry for the delayed response. For some reason, I did not get an e-mail that there were replies. Apologies.

               

              Literally the only changes I made to the original project were

              1) Length. The original project is 11 seconds long? The render time was very short... under a minute.

               

              2)  I increased all the comp layers to 3:06 (the length of the music video.) I then rendered and the render time was prox 6minutes.

               

              3) I then added a start keyframe and an end keyframe to each of the 5 layers in the project, making the opacity ramp from 100 down to 0 or 0 to 100 (some fade in, some fade out) THAT increased the render time to 1 hr 26min

               

              4) Moving all the caches to the SSD reduced the render down to 1hr.

               

              Anything I can do to reduce this (besides using Background Renderer?) Should I turn off the Multprocessing?

              • 4. Re: Yes: Another Noob Speed Rendering Question
                Rick Gerard MVP

                MP can really foul things up. Try running a test.

                 

                Rendering a 3 minute project in 6 minutes is awfully quick. That's telling me that either nothing was going on or your 3minute project was loaded into cache and the render used the cache.

                 

                An hour to render 3 minutes is not that long. There are 5400 frames in 3 minutes of video @30 fps. 1 hour is 3600 seconds. That means you were rendering at 1 frame every .666 seconds. I just ran a test on a new MBPro with a solid and fractal noise/tritone/glass setup. Total render time, 1:48. IOW about 100 seconds for 300 frames or .333 seconds per frame. Duplicate the layer, make it 3D and throw in the rest of the effects and .666 seconds per frame seems reasonable for an HD comp and an up to date system.

                 

                I've had many projects that took 20 to 30 seconds per frame and some that took 3 to 4 minutes per frame.

                • 5. Re: Yes: Another Noob Speed Rendering Question
                  Suntower Community Member

                  "An hour to render 3 minutes is not that long."

                   

                  Wow. I guess that answers -that- question.

                   

                  And I guess I'm not in Kansas anymore. If you wouldn't mind answering one more follow up... I'm now totally O/T.

                   

                  I honestly had no idea rendering was that huge a deal in AE. It makes me reconsider the whole paradigm... ie. when I was young I wrote software... back in the days when code was still 'compiled' in batches... So you had to pre-plan your work, check it 5 times because every compile was an overnight affair. It was -far- less creative because you just couldn't afford to 'try' things. You had to -know- what would work. I guess I'm wondering how people work under this constraint. IOW: if every rendering takes an hour, how to you just 'experiment'?

                   

                  Thanks,

                   

                  ---JC

                  • 6. Re: Yes: Another Noob Speed Rendering Question
                    Rick Gerard MVP

                    You check frames for look, you check motion with low rez ram previews, you work in bits and pieces just like every film editor from the invention of the process. It just takes a little experience to know what you are going to get. I've been shooting film for more than 40 years. for the first 30 all my work had to be sent to the lab for processing before I knew what I would get. After my first six months I was never surprised when I checked the film. It's just a matter of experience.

                     

                    BTW, It's a lot easier to experiment now than it was just a year ago, let alone 5 years ago. It's pretty easy to get a very good idea of what your project is going to look like very quickly, You shouldn't have to render the entire project to know. You should also not use AE like a NLE and expect to make editing decisions there. AE is used to create effects or make shots or short sequences. Films should be cut in a NLE, even commercials. Only there can you see nearly finished work in real time.

                    • 7. Re: Yes: Another Noob Speed Rendering Question
                      Suntower Community Member

                      Makes perfect sense. Thanks for indulging me. That's kinda how I work now... except that I left the AE to someone else until now.   Lots to learn.

                       

                      Oh yeah... one -other- 'last' thing: is there a table some place with a 'scorecard' that indicates how CPU intensive various FX are? IOW: something to allow one to pre-judge their impact on a render? Or is this just something one learns with experience?

                       

                      Best,

                       

                      ---JC