It's to have a excuse to have multiple GPUs. And why would I want that?
Elcomsoft's new password cracker attacks the NTLM hashing that Windows uses with a brute force method. The company claims that its GPU-powered attack speeds up the time it takes to crack a Vista password from two months to a little over three days.
Really, 15 years ago I was at university when they deployed a 16 PowerPC CPU transputer. Right now, my graphics card is more powerful than that. Crazy.