Well... the problem is simple.
In Playback mode benchmark first Write 117,6MB/s and read 154,5MB/s.
In rec mode (1080p@24fps, mlv and raw_rec, whatever), write is max 82,5MB/s and read 120,5MB/s...
and minimum for 1920x1080p@24fps is 83 or more MB/s as far as I know...
The question: is that R/W normal? What can be wrong?