This, of course, is making a big assumption: that the difficulty factor will stay the same. It has consistently increased, making earning those bitcoins signifi

This, of course, is making a big assumption: that the difficulty factor will stay the same. It has consistently increased, making earning those bitcoins significantly more difficult. Break-even for me occured at about 75 days for my 5850's, but also used a much lower difficulty (less than 5% of the current difficulty) for the beginning of that. (difficulty over the past 2 months: http://bitcoin.sipa.be/speed-lin-10k.png http://bitcoin.sipa.be/speed-lin-10k.png)