GPU2 update

The GPU2 client has been out for a while now for our newest platform, NVIDIA, and I wanted to give an update.  We're making great progress on several fronts of the beta testing of this client, with improvements to the CPU utilization and visualization (which currently is pretty much broken) coming soon.  We are also working to support multi-gpu configurations.  These are our highest non-science priorities.  On the science-side, we're scrubbing the GPU clients to make sure the results make sense.  GPU programming is challenging for many reasons, especially due to reduced precision and the complexity of using lots of threads in flight, and so it's important to make sure the results are accurate.  So far, the results look promising.  Once the GPU2 cores are  completely validated and these client issues  are addressed, we'll take the client out of beta and make a push to get an even greater adoption of this new client platform.

KNOWN ISSUES FOR GPU2/NVIDIA

Viewer doesn't work (coming soon).  This will require a core upgrade, which is in the works.

GTX280 driver version.  For pre-GTX280 cards, we recommend version 174.55 of the CUDA driver.   We recommend 177.35 for GTX cards.

CPU usage can be strange (we're looking into this).  The CPU utilization can spike on certain machines.  We have an idea for what's the issue and Scott LeGrand at NVIDIA is working on a fix.

UNSTABLE_MACHINE error if too many EUE's (not really a bad thing — a true feature of the client).  If you see this error in your client log, it means that there is some problem with your configuration.