Good question, no answer. I've just had a sequence go to la-la-land myself. A whopping two minute 45 second bit, two clips off the same initial 1980p 29.97 h264 footage with a slightly different grade in SpeedGrade and a touch of reduce grain in AfterEffects. Prior to the reduce grain, plays back fine in PrPro. After AE, it's a redline job. Render sequence for playback right?
Three hours and 45 minutes later those 4900 frames are ready for viewing. Export? Also 3:45:00. Check the hardware monitors. 4 core I7 (8 logical), 16Gb ram, twin SSD In RAID for the OS, another SSD cache, media and exports on different Internal large fast drives, GTX770 v card with 4gb vRAM? CPU never goes above 39%, mostly around 25%. Adobe products all told to use up to 12 gigs RAM, but that locks at 40%, around 6.4gb. And that v card? Not used AT ALL. Zero use of either the Gpu or its 4 gb RAM?
And I've been through settings and prefs ... replicated this on another new project with single short sequence. Where's the use of my hardware gone?
Neil