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?
Yes, it is normal for these KB 1066x 128GB cards and that's the cause of instability during recording at full hd raw. Cards I had never could continue recoding from the cold start, typically 83-85 mb/s would show up after a few attempts / bench runs. And then you need some luck. Well, not me - I returned them. But, I have to say and admit - that's still the best price/performance offering right now. Just +5..+10mb/s and it would be a winner for absolute majority of raw-video-shooters.