That stinks. But at this point if you can not fix it a couple things come to mind.
With the 980x and a set of G.Skill 2x8gb of 1866 memory, it is dual rank ram, dual rank in dual channel should be close to triple channel, single rank memory. Sell your 12gb kit and get a 2x8gb kit... Use as is, 980x dual channel ram. I am running an Asus Rampage3 with a bad ram slot, with x5660 and 2x8gb G.skill 1866 it runs just as good as my other X58 boards in BOINC primegrid and WCG
Or Sell the 980x, they are still selling for around 200$ +- or so on Ebay, sell the board as "broken" and say it works, but has "These problems" will take Westmere CPUs. Look for another board.
Sell it all and upgrade to the X79 platform and get a cheap E5-1650 xeon hexcore for 100$ or less and go that route. Reuse your memory and all other parts.
Or even upgrade to the newer Haswel CPUs. Can still use your DDR3 and the rest of your parts. Should not cost to much more than you will get for the 980x, the e5640 and motherboard.