How crackers make mince meat of passwords

The most thorough of the three cracks was carried out by Jeremi Gosney, a
password expert with Stricture Consulting Group. Using a commodity computer
with a single AMD Radeon 7970 graphics card, it took him 20 hours to crack
14,734 of the hashes, a 90-percent success rate. Jens Steube, the lead
developer behind oclHashcat-plus, achieved impressive results as well.
(oclHashcat-plus is the freely available password-cracking software both
Anderson and all crackers in this article used.) Steube unscrambled 13,486
hashes (82 percent) in a little more than one hour, using a slightly more
powerful machine that contained two AMD Radeon 6990 graphics cards.

http://arstechnica.com/security/2013/05/how-crackers-make-minced-meat-out-of-your-passwords/