Problem with 600D RAW workflow / uprezzing

[Starclassic]

OK. I am a newbie when it comes to work flow and understanding uprezzing and compression.  I import dng files to AE with raw2dng. I filmed at 1280x512 and tried to uprez through AE "render queue" at 1920x768. When I play the video back it is choppy. Is it because that my computer can't handle the rendering process at this resolution or that I am not using the right workflow. Someone please help! It would be greatly appreciated. 

[Luiz Roberto dos Santos]

Try changing the FPS of its sequence. Right click on your sequence of DNG button and go to "Interpret footage". Change from 30fps to 23,976 fps.
Moreover, it may be that your project is in another fps. In this case, do the same but with the icon of the project, change to 23,976 fps.
If the problem persists, it is likely that you do not have enough processing power to play the upscale real-time video. Render ("RAM preview" on AE or ENTER on PP), and then yes you can do it.