(2018-03-30, 22:45)3DBuff Wrote: Did anybody notice stuttering with new Pi3 B+ on 3D MVC files or is it just me?
I'm testing it right now with Turbo ON. Looks better. I need more time to fully confirm the fix.
New Pi3 B+ is continuously changing CPU clock causing skipped frames every 5 to 10s with 3D MVC files after a while.
I used to have Turbo on with RPi 3 at the beginning but then I took it out as not needed anymore. Didn't want to run CPU overclocked at max speed all the time.
B+ needs the Turbo back on. Maybe it's the new thermal profile for CPU clock or excessive power causing it to drop speed but it effects frame rate and keeps stuttering after a while (rally bad an hour into 3D movie).
Turbo on doesn't make B+ any hotter from what I can see but it takes care of the stuttering for now. It runs around 60 deg. C in my setup with limited air flow.
Turbo mode can be requested by arm (when any core is > 50% busy) or by GPU (for certain harder use cases, like advanced deinterlace, 60fps, HEVC or MVC).
Previously the logic was more basic and either side requesting turbo would result in turbo on the other side.
But, that may not be required. Simpler HEVC files don't require a turbo arm. Similarly for HW decoded 60fps files.
So we have separated the two sides and they can be in turbo mode independently. That generally results in lower temperatures.
But you may be running slightly closer to the edge in terms of performance, and as there is a little lag between arm becoming busy and getting turbo mode the performance can be lower.
So the plan was to see if the new scheme was sufficient. If not it's fairly simple to request arm_turbo for specific GPU tasks (like MVC) which would give the previous performance.
It may make sense to request the moderate turbo mode on arm (1200MHz on 3B+) which is probably sufficient for your problem but has lower voltage and temperature.
Can you point at a sample file that shows this issue? Do the drops show up in the OSD when playing the video?