3 Replies Latest reply on Oct 23, 2015 1:40 PM by stnesx24

    Another 4K choppy playback question- Mac Pro 5,1

    stnesx24 Level 1

      I recently purchased and built a system with the following specs:


      Mac Pro 5,1 (early 2009)

      2 x 3.33 GHZ 6-core (12 cores total)

      16GB DDR3 RAM

      GTX 960 4GB

      USB 3 PCI-e card

      OSX 10.11

      OS is on Samsung 850 EVO SSD

      Projects are on an external 3TB USB3 HD


      I cannot get playback in Premiere Pro CS6 on a 4K Cineform Raw file. Playback performance seems consistently choppy, no matter if I have the monitor in Full, 1/2, 1/4, or 1/16. Massive stuttering on large camera motions.


      A few things that really trip me up:

      DaVinci Resolve 12 plays back the files just fine.

      Copying the files and testing them from the SSD has no effect on the stutter.

      I have an old i7-920 2.66ghz CS6 machine that can play the same files back in 1/2 res with absolutely no stuttering issues at all, even off the USB3 drive.


      Where are any potential bottlenecks that might be causing this? The only thing I can think of is the 3 Gigabit SATA link instead of 6 Gigabit, but the files (avg bit rate 2.8GB/54sec=51.6MB/s) is still well within what the USB3 drives that test at (106MB/s) or SSD (260MB/s). And regardless, the same file playback from the USB3 drive works just fine on the old i7 machine.


      Added specs of old machine where playback works just fine at 1/2 (it does experience the same choppiness effect at Full)

      2.66 GHz Intel Core i7-920

      18GB DDR3 RAM

      GTX 660 2GB

      USB3 PCI-e card

      OSX 10.8.5

      OS is on Samsung 840 EVO SSD

      Projects are on an external 3TB- same exact drive


      Edited to add specs of 2nd machine that plays back just fine