Hello everybody!
Thanks for the help 1% and CFP!
I can record 4GB in 940x540 23,976 fps now.
I'm shooting anamorphic [Senkor 16D], with this resolution and then interpolating algorithm with S-Spline or Lanczos ... is simply stunning!
Anyway, I get up to 4GB 1280x426 nonstop too.
Some points: keep failing formatting in exFAT. Do not know if it's a physical limitation, or is it just my ignorance [most likely

]. I'm using the HDD for low-level formatting, and then creating the location with Win8. After that, I run the EOSCard [in Pelican site] and I copy the folders to Boot... but I get nothing, it does not recognize.
Report bug: I made a photographic output this morning and I forgot to do the unload module. I ended up receiving all black frames CR2. So if you are shooting, do not forget to turn off the modules!
Thank you again!
[sorry for my bad english]