Ok so i googled way more and found that the 7790 has an hash rate for bitcoins at 275~ mhash/s and for litecoins 205 khash/s.

I calculatet this:
http://s1.directupload.net/images/130408/cv5eyfmg.png

I use some higher difficulty to be prepared :x
Can this be true?

And if yes than this would be the next calculation bitcoins vs litecoins:
http://s14.directupload.net/images/130408/p4kxl5tg.png

I hope i dont do a mistake.

Thank you