Problem with SD card and bitrate increase (fast cards)

[Araablane]

So i bought myself this to ramp up Magiclanterns bitrate

http://www.amazon.com/Toshiba-16GB-EXCERIA-Class-Memory/dp/B009KGLIXI

But the problem is that it is only stable up to 1.2x (recording stops after little bit) BUT when i use my usual 8gb class 10 card it can go up to 1.4x with no problems at all.
So is my card broken or what seems to be the problem, also ive tried formatting many times and re-installing magic.

Camera is Canon 550D.

[mkorho]

Disable audio.
Only then you can record video at higher bitrate.

[Andy600]

You could try checking your SD alignment first http://www.thriveforums.org/forum/toshiba-thrive-general-discussions/15040-sd-card-issues-problems-solutions.html

[Araablane]

You could try checking your SD alignment first http://www.thriveforums.org/forum/toshiba-thrive-general-discussions/15040-sd-card-issues-problems-solutions.html

Still no change, gives recording errors when increasing bitrate.

[mkorho]

Still no change, gives recording errors when increasing bitrate.

What recording errors?
Did you disable audio?
You can't record "audio on" more than 1.2-1.4x speeds.
You can only record h264 with 3.0x speeds when you disable audio.

[Araablane]

What recording errors?
Did you disable audio?
You can't record "audio on" more than 1.2-1.4x speeds.
You can only record h264 with 3.0x speeds when you disable audio.

Says that recording has been stopped automatically, tried with audio off and still crashes after little of recording.
Well, my regular class 10 can record normally with audio in 1.4x but this super fast cant even without sound.

[cthornhill]

Perhaps you have a card issue. I have a 60D and can record at 2X normal bitrate for as long as I want (with sound off) on a SanDisk Extreme or Extreme Pro card. I can get 3X for short burst, but find 2X more reliable. You may need to try another card, and I suggest keeping the ISO low (that appears to help) and turn off any tools you don't need in the GUI. I suspect the card - remember that you may be limited by your controller depending on your camera (mine is limited to not much more than 20MB/sec). 5DM3 or M2 with CF are faster.