5DmkIII preliminary basic Compact Flash card speed tests yield:
Sandisk Extreme Pro 128GB 100MB/s UDMA 7 CF burst ~82MB/s with ~73MB/s sustained write speed @ 1920x960. It would randomly drop frames at 1920x1080 but did complete the 4GB size limit before ceasing. It was the only card of the trio that could record 1920 vertical lines whilst simultaneously recording the 1920x1080 H264 "proxy" to the same card. In fact, it's sustained speed did not waiver whether or not the H264 files were being written.
Lexar Professional 32GB 1000x UDMA 7 CF burst ~87MB/s with ~82MB/s sustained write speed @ 1920x1080. It was the only card that could repeatedly sustain full 1080p for the duration of the 4GB size limit.
Delkin Devices 32GB 1000x UDMA 7 CF burst ~69MB/s with ~63MB/s sustained write speeds @ 1920x840. It was the poorest performer with random dropped frames above 840 horizontal lines. It would complete the duration of the 4GB size limit at 1920x840, but no higher.
None of these cards' write rates seemed affected by panning or tilting or complicated visual patterns in frame.
Global Draw was always on, but only for information overlays, all of the graphical overlays within frame were turned off.
The camera got warm, but not hot, and when the cards were pulled, they were likewise only warm. Nowhere near as scalding as an SSD mag removed from a Blackmagic camera. Never a temp or buffer warning from Canon firmware or Magic Lantern software.
In the next few days I will post a blog with test footage for those that are interested:
http://shop.texasmediasystems.com/blog.aspThanks so much to the committed ML dev team and the forum members who contribute!
best,
-Colemar Nichols
