hi, i was getting to the prompt "NMI handler (perf_event_nmi_handler) took too long to run" and my system was just freezing. i had a duel pci gpu configuration with the single or duel gpu pci type of HW-card used as the switch between each mode. i removed the second gpu and flipped the switch back to single and my system booted perfectly, with no errors. im guessing the extra HW was too much of a strain for the system to handle...