XMP is an approved OC for your Ram that comes from the motherboard makers. Unless you've altered something in your Bios, I would disable it while you check and see whaty is happening. Whole troubleshooting procedure basically goes by process of elimination, you can turn things back on or enable Overclocks as long as you are sure it's not the problem issue. But if you're passing cinebencj multiple times I would leave it enabled.