The files I am currently working on are drum scans of B&W negatives, both 120 format which are 220mb in size and 35mm which are 60mb.
From LR4, I edit in SEP2 choosing edit with LR adjustments, Profoto RGB, 16 bit, 360 DPI.
After editing and saving back to LR4, the photos are very pixelated compared to the original with extreme loss of detail and smoothness.