Speed of CF card for 7D video ?

I've never taken a video with my 7D or for that matter any camera. This summer I would like to try some video of wildlife. My question is what would be the minimum requirements for a CF card. I thought I read somewhere that 8mb/s is the speed required.Would a fast card 40mb/s just be overkill? Your thoughts please.

I use 133X or 20MB cards without any problems.

I generally prefer to use high-speed cards, but not necessarily because it allows faster shooting, I just like the file copy speeds more and they're more future-proof in case I move up to faster camera. Video files are big with a capital B, so file copy speed does matter, at least to some people it does.

In any case, the card is the cheapest component of the camera, so I can't see why you would want to pinch pennies on a $100 card, when you've spend thousands for the body and glass.

Magic Lantern is already being ported to the 7D, so soon you'll have the ability to crank up the bitrates up as high as you want, when that rolls around even a 1000x card might sound like a good idea.