I have had a little time this morning to try some of the suggestions above .
3400 MHz just doesn't seem doable . As soon as I choose 3400 MHz the memory either resets on re boot to 2100 MHz or the bios resets on reboot back to original settings . Tried it with all the suggestions above upto 1.45v and with IF set to 1800 & 1700 . Setting Cas latency to 18 made no difference and gear down was in auto but set to enabled made no difference .
Currently running at the step below 3400 MHz and if set to 1667 @1.42v . System seems stable and have run a windows memory test without issue .
3400 MHz just doesn't seem doable . As soon as I choose 3400 MHz the memory either resets on re boot to 2100 MHz or the bios resets on reboot back to original settings . Tried it with all the suggestions above upto 1.45v and with IF set to 1800 & 1700 . Setting Cas latency to 18 made no difference and gear down was in auto but set to enabled made no difference .
Currently running at the step below 3400 MHz and if set to 1667 @1.42v . System seems stable and have run a windows memory test without issue .