4 Replies Latest reply on Nov 9, 2013 11:17 AM by pablo antoine

    during ram preview ae cc wildly accessing system drive

    pablo antoine Level 1

      After effects cc builds a ram preview of a 1920x1080 file without problem, the cache is on a secondary HD drive or SSD with plenty of speed and free space and there are 16 GB of RAM - but when the ram preview starts to play, sooner than 15 seconds it will become stilted and the system drive will start crackling like crazy. The activity of the system drive is so intense that the mac becomes sluggish and irresponsive.

      An interesting aspect is that if it will keep playing as stilted as it is, after 2-3 cycles of the same ram preview range, the playback will become more fluid.

      This happens - unbelievable- on a mac pro with 16 GB of RAM and latest Lion OS. All the files are on different drives than the system, and the cache was  hard drives or  ssd - all high speed, all internal drives.

      And the latest surprise - assuming that maybe the system drive got too fragmented, I changed it for a brand new hd with all the programs transfered on the new drive from a time machine backup.

      Same insane activity of the system drive at the less than 15 sec mark of ram preview playback.

      Anyone encountered this wild accessing of the system drive by after effects cc during ram preview?

        • 1. Re: during ram preview ae cc wildly accessing system drive
          Todd_Kopriva Level 8

          It sounds like your computer is swapping the contents of RAM to the hard disk---which is what happens when you don't have enough RAM allocated for After Effects. Show a screenshot of your Memory & Multiprocessing preference settings.

           

          See this:

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

          • 2. Re: during ram preview ae cc wildly accessing system drive
            pablo antoine Level 1

            Good Points - you are partly right and my settings are attached here at the end.

            I fiddled with them for a while (and even now they are too much in favor of AE) because it looked like they were not changing much from that weird behavior.  The fact is that I tried most values - from max to minimum for background processes -nothing changed much except the speed of the rendering. The stumbling and the wild accessing of the main drive continued no matter what after the 14 seconds mark of all HD renderings.

            Seeing than no one can help here either, yesterday I tried changing everything else in the Preferences to see what makes any difference in AE CC 12.1 and get over with this behavior.

            And 2 unexpected settings really made a difference for me:

            1-the QuickTime Video Preview, unchecked, ended the inescapable stumbling at the 14 s mark. I don't know how, but it made a crucial difference.

            2- at the Memory page I checked the Reduce Cache size when system is low on memory. It prevented the RAM preview from using all the ram and leave the mac processes starving and turning the machine sluggish.

            The Ram preview now happens in an interesting fashion (I have Memory Cleaner, a benign app, really useful to show how much RAm you really have at a given moment on a Mac). The green line above the timeline now expands until RAM decreases to low numbers like ~500MB RAM left. The Preview processing then waits a matter of seconds until the numbers increase again beyond 1.5 GB and then continues to extend the line - and so on until it reaches the end of the work area. There is no crackling anymore (accessing system HD).

            I am using only SSDs and auxiliary HD drives (for output and source files) and all Ram previews now are completely quiet.

             

            So, I have found my solution so far. But there still is a question the AE designers might want to think:

            If they know that AE will unload the RAM onto the system HD, why don't they insert an option in the Prefs to allow this unloading to happen onto any secondary drive - choosen by the user.

            A secondary drive unload at least will not interfere with the system processes - turning the mac sluggish and add insult to injury.

            My numbers below could look tight now, but the previews are really fast and I quit all secondary processes  on my mac when AE is working.

            AEPrefs112013.jpgAEQset.jpg

            • 3. Re: during ram preview ae cc wildly accessing system drive
              Todd_Kopriva Level 8

              > If they know that AE will unload the RAM onto the system HD, why don't they insert an option in the Prefs to allow this unloading to happen onto any secondary drive - choosen by the user.

               

              This swapping is an operating system process, not an After Effects process.

              • 4. Re: during ram preview ae cc wildly accessing system drive
                pablo antoine Level 1

                Thank you Todd,

                Are you reading minds? Can you see posts while they are still edited?

                The Blog is really great - thanks for everything.