Hey, just trying to shed some light on what is going on. Coming from a 980ti SC / 4790K and recently built a new 1080SC / ryzen 1800X.  Everything is new including the hard drive for the OS installation.  1080 operates perfect at stock settings.  Precision allows me to set Power and Temp target sliders to 120% and 91 deg but the moment I try to set manual changes to core frequency and memory clock, games lock up on load screens and 3D mark crashes out with the messages 'cancelled by user'.  I'm not pushing for hard clocks as I've tried increments from 5MHz to 100Mhz changes and it still expresses the same behaviour.   I've read that it sometimes requires that the OSD is disabled, but aside from the little check box on the main interface, is there another one in the menus that I'm missing?   
 
I have also tried afterburner and it gives the same result.   Running latest Nvidia driver released last week and installed latest precision with prior proper version uninstalling including registry clean. 
 
Any help would be much appreciated. Thanks! 

Thanks.  I've got no issues with nvidia cards and precision on my 4790/980ti rig or my older AMD 8350/680 rig.  Just seems that this current combination with all new parts and no other software aside from a fresh copy of windows (on a new drive), new geforce drivers, steam, 3dmark, project cars, grid autosport, tomb raider and system drivers via the AMD Ryzen driver package (excluding graphics drivers) seem to have gunked up the system.  Let me know what you find with your new rig.