Cineform file size bigger than prores

Hi,

I started to use Cineform codec on my windows machine when I need to send clips with alpha channel to an editor that is on Osx.
Before we had a fully ProRes workflow.

I am pretty happy with the results and files works smoothly on both workstations, windows and osx.

Only today I noticed something weird in the file sizes:

5 Second clip from after effects to AME (using the new "queue in AME" from render panel) in Cineform 12bit - no alpha:

quality 4 > resulting file is ~700MB

quality 3 > resulting file is ~620MB

quality 2 > resulting file is ~330MB

Tried on my osx workstation to export same file (same workflow) in prores422 and it was 73mb, same quality side to side compared with the Cineform export.

Is normal that Cineform results in 10x bigger files?

Can something be wrong in my workflow?

Thanks.