I'm using the VSE (Video Sequence Editor) to set up the timing of my movie. I have 30 images from a storyboard, in rather low resolution (1000x1000 px or less, 100-200kb in size) in JPG format.
I've put them in a sequence, first by importing them all as an image strip, then separating them into images. I have no effects other than "Image offset" (not an effect?) in the right hand side toolset to center them on the screen.
When I play the video, render settings set at 30 fps, it plays back at 30 fps in the beginning, but after 5-6 images, it plays at 15-17 fps. I have Sync Mode set to Frame dropping, but apparently it's not dropping frames.
It's not like it's any heavy animation, linked scenes or anything, just still images, changing every 2-3 seconds.
Why isn't it dropping frames, and how can I improve playback speed? I have set the Sequencer/Clip editor > Memory cache limit setting to 2048 MB. Should I need more than that to cache 30 images?
I'm using a MacBook Pro Late 2016 2,7 GHz Intel Core i7 in Blender 2.78 and MacOS Sierra 10.12.3.
Here's a screenshot, if that helps in any way: