Thanks for the input guys.. I run around 1,8-1,9V Vdimm constantly so uncore shouldn't be a problem (I'll try with high uncore at 6x mult next to verify).
The thing is that even the 8x mult seems unstable and even went so far as to up the bios (rebooted during linX and went into a reboot loop.. had to remove battery for 2h to get it back up lol).

What helped a great deal was reducing the Command rate to 2T, I guess with 6GB 1T can be rather harsh on the IMC.