System just shut off, no blue screen, no message when it came back up, my blue screen viewer isn't picking up any dump file from it.  And it didn't restart on its own like it does after a blue screen.  Thought it could have been Poem causing problems, it finished all of the tasks before hand, thought maybe it something going from Poem to another gpu project, nope, Poem finished up about 10 min before it started PrimeGrid.  Thought it was a heat issue maybe since I raised the oc about 18 hours ago, nope, it's running about 3C cooler crunching on the freed threads after poem finished, and if it shutdown for heat, I have bigger problems since it holds between 56-57C at 4.3, it starts downclocking to drop temps around 62C and if it's getting hot enough going from 4.3 to 4.4 where downclocking doens't help the temps, I'm thinking maybe Poem didn't completely release the threads it was using and after 10 minutes of trying to share, it didn't know what to do?
But it seemed more like a shutdown form a power outage than anything else....  Not a gpu heat issue, currently running Genefer and they are picky with heat, it would have error'ed out....
Any ideas?  Don't want to try to reproduce it, it went down in the middle of editing some code for homework, luckily it was only two lines I was working on since the last save.  It just seems weird that it would go out like that without a blue screen or warning or even giving the option to start in safe mode while booting....

My first thought would be a power supply related issue that caused the shutdown. Do you have a spare power supply that you can test with? The other thing to check is to make sure the system did not go into a sleep state for some reason.

Not one that isn't being used for something else, no....  Could it be drivers?  I updated them about the same time I adjusted the oc and did the app_info for Poem.  Only wondering if that's the cause now because since updating, I keep getting errors with GPUGrid and the application crashing and then the 460 dropping back to stock voltage.  I set the voltage again and it gets stuck in 2d clocks....  It wasn't working on any GPUGrid units when it went down yesterday, but I guess it could have been a combination of things, too....

Not sure if it's the new drivers or my gpu oc not being compatible with the cpu oc, but I had to lower the gpu oc to get GPUGrid to run.  The oc worked fine for it before the driver update and bumping up my cpu oc....