I have 7 h264 .mov files and i wanna use after effects for cuting. The files have together 1.5 GB and when i render them in after effect using quicktime h264 again the file size is way to big. Around 8GB+. What can i do ?
AE is not an editing package. It can edit, but is not designed for that. You do not have real time playback unless you render, so that limits you to the amount of RAM you have and the resolution of your preview. Use Premiere Pro for editing and AE for graphics, effects, compositing...
H264 is not the best format for work in AE. Due to compression you loose a lot of information. For best results in AE convert your footage to an uncompressed format and then do the gfx/vfx/compositing. This will result in large files.
Do not compress from AE. Render uncompressed and then use a package like Adobe Media Encoder to compress.
So your workflow should be like this:
Edit in Premiere > GFX/VFX in AE and render uncompressed OR use Dynamic Link to convert clips or Sequences to AE compositions from Premiere > replace clips in Premiere if you work on them separately, if not, just render the final out of Premiere (Queue render and choose preset in Encoder- plenty of H264 options, you will want to choose 2pass with a Variable bit rate)