Nvidia has nearly cut in half their LuxMark scores with the introduction of OpenCL 1.1 compatible drivers. There has been a lot of complains in their OpenCL forum but yet no explanation or fix for the problem. LuxMark 1.0 code (and test scene) starts also to be a bit "old" (and too simple) for todays GPUs. We are actively working on LuxMark 2.0 (a beta is available here: http://www.luxrender.net/forum/viewtopic.php?f=34&t=7671 (registration required)). There is already some eye popping result scored with 4xHD7970 in LM 2.0 That GPU is damn fast in GPU computing tasks.