recording capacity of CF and red drive

[nigelsmith]

I am finding that I get around 17 minutes of 2K 2:1 25fps Redcode 28 footage on one 8Gb CF card.
Yet the wikipedia article on Red claims that I should be able to fit around 34 minutes. How is that?

And another question...
if one 8Gb card can hold about 5 minutes of 4K footage, then will the RED Drive at 640GB hold over 6 hours?

Thanks for any info....