3 Replies Latest reply on Jan 19, 2011 2:18 PM by FrankinMD

    Where's the Bottleneck??

    M-323 Level 1

      hello everyone in visual effects land.


      over the past week or so I have been trying to tweek my G5 into top performance.


      its a dual 2.5ghz machine.


      I upgraded the boot disk to a 250G

      upgraded Disk 2 to 1Tb


      over all I have just over 4Tb of space now so there is lots of room, before I was under 10% left on disk 1 which, I could see would be causing some problems


      so I freed up disk space, ran Disk Warrior -- it said it fixed directories, files etc


      I have a 2 hr show that I just wanted to add an effect to. its a 3rd party effect that reduces grain. before I did all this optimization work, I tried rendering the same file out and it was estimated at 32 hrs! I let it run for over a day and at the end, the file was corrupt or something. I wouldn't work.


      so now, I dont have a time estimation, but the progress bar is moving painfully slow.


      I have it set up to read from an external USB 2 drive, into the G5 and the output is to the internal, brand new, 1TB scratch disk.


      its encoding, one frame by frame! currently at 11000 of about 200,000frames and its been running for at least an hour!


      I estimate this is only about 5%.


      therefore 100% would be like 20 hrs.


      first, why do I not have a time estimate on the program? I'm pretty sure it gave this to me last time I ran it. now I have to make my own calculations.


      2nd, would it have helped, if I moved the video files off the external and onto the new internal scratch disk? (I started to do that but it estimated 6hrs just to move the files so I abandoned that idea)


      3rd Im sitting at 4.5GB of ram right now and I have 6GB on the way in the mail. When they arrive, I will take out the smaller sticks, replace them with the 6GB, bringing my total to 8 (max this machine can take) will that help anything? or is the bottleneck somewhere else?

        • 1. Re: Where's the Bottleneck??
          Mylenium Most Valuable Participant

          Bad news for you: The bottleneck is the effect. Temporal effects always work linearly, chewing away one frame at a time while analysing strictly linear forward and backward. That being so, footage I/O is a neglectible factor. More RAM might allow the analysis to hold more frames in memory and thus be a bit more efficient, but it won't do miracles. You really only could improve this with a better processor, but even then, since most temporal effects cannot be parallelized and thus are not safe for multiprocessing, it might not make much of a difference if you have the latest 12 Core MacPro... It's really inherent in how this all works compounded by the fact that a G5 is underpowered by today's standards plus it cannot make use of accelerated processing by ways of graphics cards, too, which would also hugely help if you e.g. used Magic Bullet Denoiser. You're really a victim of circumstance. As for file corruption issues - render to image sequences and assemble them in a second pass (which would be reasonably fast after the initial processing)! The amount of footage you are processing in one go is quite huge and there is any number of things that can interfere. The status bar update is anotehr thing, but might simply be a glitch in the UI or the plug-in not correctly communicating its processing status to AE.



          • 2. Re: Where's the Bottleneck??
            M-323 Level 1

            ok well, I guess thats not what I wanted to hear but as long as its not something Im doing wrong, I guess we just let it run its course. and its nice to hear that throwing more money at it will not really help.


            I was worried that it was the output format that I selected. I chose Mp4 for DVD I hope thats a good enough output.

            • 3. Re: Where's the Bottleneck??
              FrankinMD Level 1

              If you export to MP4, you may see a shift in color. H.264 seems to have an issue with color fidelity in a lot of situations, including when rendering from After Effects. Currently I am rendering to an intermediate format and then using a third party encoder to transcode to MPEG4.