Testing out some Raw 14bit recording on my 5D mark III with Magic Lantern.
Shot at 1920x1080 with a Canon 24-70mm f/2.8 II and Canon 70-200mm f/2.8 II
Used a Komputerbay 64gb 1000x card. I had no dropped frames. My benchmark test averaged around 94mb for the write speed. That was more then enough for 1080p continuously till the card filled up.
I used RAWMagic to convert the .RAW file to .dng files, Sent the files to Photoshop to tweek the image, then used After Effects to create the video file from the .tiff files I exported from Photoshop. Lengthy workflow, but the image is worth it when aiming for the highest quality.