The five-server system uses a relatively new package of virtualization software that harnesses the power of 25 AMD Radeon graphics cards. It achieves the 350 billion-guess-per-second speed when cracking password hashes generated by the NTLM cryptographic algorithm that Microsoft included in every version of Windows since Server 2003. As a result, it can try an astounding 958 combinations in just 5.5 hours, enough to brute force every possible eight-character password containing upper- and lower-case letters, digits, and symbols. Such password policies are common in many enterprise settings. The same passwords protected by Microsoft's LM algorithm—which many organizations enable for compatibility with older Windows versions—will fall in just six minutes.
What I find to be interesting about this article is VCL.
VCL is an OpenCL cluster platform that can transparently run OpenCL applications on many GPUs in a cluster, as if all the GPUs are on the user's computer.