11 Replies Latest reply on Mar 14, 2013 1:44 AM by Ash J Williams

    Percentage of RAM used

    Ash J Williams

      Hi all

       

      I have been playing around with memory settings for AE CS5.5 and taking some advice from here:

       

      blogs.adobe.com/toddkopriva/2010/10/please-try-recommended-memory-settings-for-after-effec ts-cs5-and-give-feedback.html

       

      and here:

       

      http://forums.adobe.com/thread/734343?start=0&tstart=0

       

      With variety different compositions, and different memory settings I have noticed my 'RAM: % used of 24GB' in my Render Queue window (at the bottom of the window) is always pretty low. Anything between a few % and 25% ish.

       

      Is this just showing me the RAM used for the foreground CPU and not the collective CPUs?

       

      Any info is much appreciated.

       

      Cheers

      A

        • 1. Re: Percentage of RAM used
          Rick Gerard Adobe Community Professional & MVP

          What you are seeing is the percentage of ram used to process the effects and the frame. AE renders in the render cue a frame at a time. The bigger the frame and the more that's required in that frame to process the pixels the more memory used. A SD comp with a particle system like Trapcode's Particular that is generating 60,000 particles may use more memory than a 4K comp that is just doing simple color correction. Because of the way AE calculates a frame at a time there is no way to force the program to access more memory than it needs.

           

          You may see higher memory usage in the Adobe Media Encoder because that rendering engine is capable of multi pass renders. The AME encoder, however will only use one set of CPU cores. That may not be all bad. I'm almost always rendering something with AME while I'm working in another app, and since I seldom have MP turned on in AE I don't see a performance hit.

          • 2. Re: Percentage of RAM used
            Ash J Williams Level 1

            Cheers Rick, interesting stuff.

             

            Rick Gerard wrote:

             

            AE renders in the render cue a frame at a time.

             

            Is that true when you have Render Multiple Frames Simultaneously turned on and more than one CPU is used?

             

            I initially made the assumtion that I believe many people make, that if you give AE enough RAM, it will use it all and render faster. I appreciate that even with all the RAM in the world it has other limitations on how fast it can render a frame.

             

            A

            • 3. Re: Percentage of RAM used
              Rick Gerard Adobe Community Professional & MVP

              The render Cue can only process one frame at a time. Each one is unique. If you have MP turned on (render multiple frames simultaneously) then the CPU can render more than one frame at a time and therefore use more memory unless you are using an effect that is not optimized for MP rendering. Many codecs you use for rendering are not MP aware. Many plug-ins are not, and therefore, your renders will take longer than they would with MP turned off because AE will annalize the frame with multiple processors, try and make it work, then decide that it won't and revert to rendering with one processor for every frame. That 'figuring out' process can hang up the machine and make things run very slow or not at all.

               

              Be very careful with MP processing in AE. I can't remember the last time I had it turned on. Maybe it will get better in the next release. Maybe more plug-in manufacturers will make their plug-ins MP aware.

              • 4. Re: Percentage of RAM used
                Ash J Williams Level 1

                Bare with me here Rick...

                 

                Are you saying that MP is individual physical CPUs rendering more than one frame at a time?

                 

                I thought that MP was a case of AE using say 3 CPUs to render 3 frames at a time. One render per CPU simultaneously.

                 

                My assumption on this comes from other posts where the use of more than one CPU is described as having more than one version of AE running – 'Think of each background instance as a mini After Effects'. Hence I wasn't sure if the 'RAM: % used of 24GB' in my Render Queue window would be showing the RAM used for all 3 or just the foreground one.

                 

                I may have the wrong end of the stick on this one...

                 

                A

                • 5. Re: Percentage of RAM used
                  Rick Gerard Adobe Community Professional & MVP

                  What happens with MP processing is that one CPU renders a frame and at the same time the other CPU's try and render other frames at the same time. You don't get multiple CPU's working on the same frame. AE doesn't work like that. Most MP aware software doesn't either. The standard multi threading usage is to divide up the tasks and send them to a CPU to complete. AE's 'task' is to render a frame. The MP processing in AE isn't smart enough yet to divide up a frame into pieces and send the pieces all to the renderer. I've been asking for line rendering for a long time. AE builds a whole frame at a time as a single process. That's why AE's MP rendering is a little wiggie. (wiggie is almost buggy)

                   

                  I'm also saying is that if your project is MP compatible that each CPU can render a frame at a time and that more than one frame may be rendered simultaneously, but if there is anything in your project that is not MP aware each CPU will try and render, get confused because the something like a codec or an effect is not MP aware, and the system will hang until it gives up and tries to render with one CPU. When that frame is rendered AE will start over with the next frame try and send multiple frames to multiple CPU's and try to render multiple frames simultaneously, get confused, fail, and finally render a frame with 1 CPU and then start the process again. This is why throwing in an effect that is not MP aware for one shot that only lasts 10 frames in the middle of a comp would, without that effect, efficiently use MP rendering  will cause the render to hang up and dramatically increase render time or fail completely. That's why I seldom of ever have it turned on.

                  • 6. Re: Percentage of RAM used
                    Ash J Williams Level 1

                    Cheers Rick

                    Rick Gerard wrote:

                     

                    What happens with MP processing is that one CPU renders a frame and at the same time the other CPU's try and render other frames at the same time. You don't get multiple CPU's working on the same frame. AE doesn't work like that. Most MP aware software doesn't either. The standard multi threading usage is to divide up the tasks and send them to a CPU to complete. AE's 'task' is to render a frame. The MP processing in AE isn't smart enough yet to divide up a frame into pieces and send the pieces all to the renderer.

                     

                    Yup, thats how I thought it worked.

                     

                    Didn't know codecs or effects could cause issues though, I will keep that in mind, very helpful.

                     

                    Bigh thank you.

                    A

                    • 7. Re: Percentage of RAM used
                      Ash J Williams Level 1

                      Ha ha!

                       

                      I just realised, I'm still no more sure if the 'RAM: % used of 24GB' in my Render Queue window is showing RAM used by one CPU or three...

                       

                      A

                      • 8. Re: Percentage of RAM used
                        Mylenium Most Valuable Participant

                        You could always use task manager/ resource monitor to verify?!

                         

                        Mylenium

                        • 9. Re: Percentage of RAM used
                          Ash J Williams Level 1

                          Cheers Mylenium.

                           

                          I looks like that % is of all RAM being used across all the CPUs.

                           

                          For the sake of speed, it does seem a pity that AE is not taking advantage of all of it's allocated RAM or all the RAM available to it for rendering.

                           

                          Thanks for the help guys.

                           

                          A

                          • 10. Re: Percentage of RAM used
                            Todd_Kopriva Level 8

                            You've gotten some good information already on this thread, but I just want to sum up a few answers for clarity:

                             

                            > I have noticed my 'RAM: % used of 24GB' in my Render Queue window (at the bottom of the window) is always pretty low.

                             

                            That number is only telling you how much RAM the foreground process is using; it doesn't include how much RAM the background rendering processes are using. This number really doesn't tell you anything useful if you're using Render Multiple Frames Simultaneously multiprocessing.

                             

                            > I initially made the assumtion that I believe many people make, that if you give AE enough RAM, it will use it all and render faster.

                             

                            Yes, but not at the expense of taking RAM away from other software and forcing the operating system to swap the contents of RAM to the hard disk. That's why the recommendations are made here about reserving RAM for other software:

                            http://blogs.adobe.com/aftereffects/2009/12/performance-tip-dont-starve-yo.html

                            • 11. Re: Percentage of RAM used
                              Ash J Williams Level 1

                              Todd_Kopriva wrote:

                               

                               

                              That number is only telling you how much RAM the foreground process is using; it doesn't include how much RAM the background rendering processes are using. This number really doesn't tell you anything useful if you're using Render Multiple Frames Simultaneously multiprocessing.

                               

                              From having a quick look at the Activity Monitor I thought it was showing how much RAM was being used by all the CPUs... my maths must be worse than I thought!

                               

                              Again, thanks for the input everyone

                               

                              A