Hey all, I've had my trusty 2500k running at 4.5ghz stable at a safe voltage for roughly 5 years. Recently, I have started to get hard crashes sporadically; no BSOD, locks up and restarts, sometimes takes a few boots to get back to BIOS and to Windows. System setup: Gigabyte z77x-ud5h (seven years old) 16gb (4x4gb) Corsair XMS, all matching (one pair at seven years old, second pair maybe four years old) Seasonic x650 (three years old) GTX960 (three years old) After the errors started happening, I tried upping the voltage a bit, but that didn't help. Then, I reset everything to stock (no overclock, even went and loaded optimized defaults at bios) but the problems still persist. I have tried: reinstalling windows 10, twice ran memtest on ram, passed a four hour test flashing new bios firmware cleaned case, no heat issues, all case fans run ran prime95 for a few hours with no errors With everything stock, ran prime95 and furmark together for an hour, no issues, no errors. Stopped, went and researched this more on the web, crashed while scrolling a forum. I cannot reproduce this issue, and I haven't solved it by going back to stock. With no BSOD, I am assuming it is a hardware issue. Could it be a faulty motherboard? Not sure how to test/verify that. Any help is greatly appreciated, I am struggling with this one.