I found a very nice and fast software for cracking hashes, like sha1 and md5. It went through almost 1000 million hashes per second on my computer, compared with Cain which did about 6,5 millions per second. But I have only a half broken ATI 4870. This is what the website says about 5970:
Recovery speed on ATI HD 5970 peaks at 5600M/s MD5 hashes and 2300M/s SHA1 hashes.
And that is freaking awesome!