I have been fine tuning my 24/7 settings and landed on 10x420. Anything higher than 4.2 ghz requires big voltage jumps. Also at 1680 mhz on the ram I can run 7-6-5-16 timings, whereas at 1800 mhz I have to loosen to 8-8-8-20 in order to pass OCCT. (Not sure what the deal is with that.) Anyway, overall I'm pleased with the memory performance especially the low latency: