One more thing I noticed - the issue is the memory slot closest to the motherboard. Even a single 2133 DIMM in that slot will make the system unstable. So there is a difference in how the BIOS configures the memory in those two memory slots with the slot away from the motherboard being the only one that can run DDR3 2133 stably.
The reason why you are having stability issues on this device is that the NUC supports memory up to 1600MHz. Honestly I am surprised to hear it is working at 2133MHz single channel configuration.
Please configure the BIOS to run memory at 1600MHz as this is the supported configuration and let me know the results.
Here you can check the memory speed supported for this NUC:
The problem is that in BIOS 28 and later all performance settings have been hidden, including the one to set memory settings manually. Please notice that the BIOS sets the memory to run at 2133 automatically and in BIOS 28 and later there is no easy manual override to make it run at 1600.
Yes, I can use the search feature to find those settings and fiddle around with them but is that the official story? Especially that after purchasing the memory kit and inserting it into the NUC the unit is unstable out of the box and even going into BIOS there is a 50/50 chance that it will freeze on you before you have a chance to first use the search feature and then set all those memory settings manually in the search results window.
Here's my suggestion for BIOS changes:
- Change the auto configuration of memory in BIOS to cap out at 1600 instead of the max SPD setting
- Keep manual configuration possibility there for those who purchase 1866 kits as those are stable
- Add back the capability to change VTTDIO and VTTAIO offsets. Those values are there but in read only mode since BIOS 28. Those values need to be adjustable for those who buy 2133 memory and want that speed to be stable.