well, one of the ram sticks i'd ordered is probably dead. i can't tell for sure since i haven't gotten my new board yet and the one i tested with is known for bad slots, but i tested the sticks in basically every config including the one that previously worked fine, and i swapped around just in those slots too and consistently 1 stick errored out. 

happily however i still have 32gb of ram, since i've put the 8gb i already had (4x2gb) with 1 of the new 8gb sticks for 1 cpu, and the other 2 working 8gb sticks for the other cpu, so i still have a 32gb config properly set up for numa. 

also the seller of the memory is very nice, i will test with the new board tommorow, if it turns out the stick is indeed toast i can just send back the 1 broken stick and get 25% of my money back.