Re-reporting about testing 3 Canon 50D cameras. This morning after going through a series of ML feature sets, specifically global shutter, histogram, and 3:2 display mode, I was able to pass by the 52MB/s recording limit. I am using a 64GB 1000x Komputerbay card, the same card that was writing continuously in a 5:3 aspect ratio on a second Canon 50D camera. Anyway, in my last post I had mentioned that the serial number looked like a much later serial number... It made me wonder if there was some type of Canon factory quality control issue... Rest assured, this is not the case. I had a breakthrough in recording tests after adjusting the ML feature sets and seeing a difference in the write speed per second and also the number of frame captured before the recording stopped. In other words, I was fine tuning the camera. And after shooting about 20 videos in less than 3 minutes and referencing the write speed and frame per second number the camera suddenly began recording upwards of 60MB/s. Interestingly, the tests before, using the same setting as that of the second camera, were only producing a maximum of 54MB/s write speeds. I believe that I was able to reach this recording speed by turning on and off global shutter, histogram, and 3:2 aspect live view mode. It's like the monster woke up by toggling these feature sets on and off. They are now currently turned on. And I have no trouble recording at any resolution.
Sorry that I don't have an exact answer as to why the camera wasn't recording continuously past a 2:1 aspect ratio, however, the camera is now capable of writing a 4GB file in 3:2 aspect ratio with 3-4 bars on screen at a stable 67MB/s write speed.
Got the day off from work... Will be testing away!!! Woohoo! Thanks ML! Thanks everyone!