StrongGlad writes with a story at ZDNet describing how it's getting easier to use GPU processing against passwords
once considered quite strong.
"Take a cheap GPU (like the Radeon HD 5770) and the free GPU-powered password busting tool called 'ighashgpu' and you have yourself a lean, mean password busting machine. How lean and mean? Working against NTLM login passwords, a password of 'fjR8n' can be broken on the CPU in 24 seconds, at a rate of 9.8 million password guesses per second. On the GPU, it takes less than a second at a rate of 3.3 billion passwords per second. Increase the password to 6 characters (pYDbL6), and the CPU takes 1 hour 30 minutes versus only four seconds on the GPU. Go further to 7 characters (fh0GH5h), and the CPU would grind along for 4 days, versus a frankly worrying 17 minutes 30 seconds for the GPU."