Created attachment 840656 [details] stack trace from the system log also a kernel with recovery parameters ( apm=off noresume edd=off powersaved=off nohz=off highres=off processor.max_cstate=1 nomodeset x11failsafe ) was not stable. The system has an Intel(R) Core(TM) i7-2600K CPU (Sandybridge architecture https://ark.intel.com/content/www/us/en/ark/products/52214/intel-core-i7-2600k-processor-8m-cache-up-to-3-80-ghz.html).