With help from members, I have compiled a list of card speeds with Magic Lantern. Feel free to add more results, details at the bottom of this post.
The results for all cards and cameras tested, can be found here:https://www.dropbox.com/sh/mfzdpkz82k2zc8n/AABR4fm_T1pURmy2sUmpJaIsa?dl=0
Posted results in this thread that haven't followed the requested testing procedure have not been included in my dropbox link, testing in playback mode etc. Please follow the instructions below if you would like your results included.
The fastest CF card results I have, show the KomputerBay 64GB 1000x @ 93MB/s.
However, all KomputerBay cards tested above 85MB/s on the 5D3, and the Lexar 64GB card I have results for, also benchmarked above 85MB/s.
Based on the results of one card, the 5D2 appears to be around 15MB/s slower then the 5D3.
Higher frame rate modes in Canon settings, results in slower speeds. That is to say, 24p modes are fastest, and 60p modes are slowest.
Crop mode in Magic Lantern raw recording, switches to 30p mode.
Cameras have hardware limits to card speeds, it doesn't matter how fast the actual card is. These speeds (and other useful information) can be found here: https://docs.google.com/spreadsheet/ccc?key=0AgQ2MOkAZTFHdFFIcFp1d0R5TzVPTVJXOEVyUndteGc#gid=5
To perform the benchmark, select the benchmark option in the debug menu, then choose the Card R/W benchmark option.
When the benchmark is complete, a PPM file (BENCH0.PPM) will be on the card that has ML installed, and you can use the free image viewer Irfanview
to save the PPM as PNG.
Upload the files to a free image host
and post the links here, preferably using the img tags.
Please include the camera used and card type +capacity, and test in movie mode with Global Draw OFF.