CPU/NB voltage when running 4 sticks of RAM.

[queueball]

Thanks in advance for any help you all can give.
I was running a computer with 2 x 4GB RAM OC from 1600 to 2133 for a few weeks with no problem using the built in OC profile in the BIOS. I decided to add 2 more sticks of RAM and it will not run. I did my due diligence and found that I might need to increase the CPU/NB voltage to get the memory controller to handle all 4 DIMMS being used. I raised the voltage .05, .075, and .1 along with a few others and I can't get it to boot past the login screen without crashing. I should mention that I have the DRAM voltage and timing set to the specs on the memory.

My question is; should I start with the lowest voltage increase and just reboot after each incremental increase? Does anyone have a rough idea how much I should be increasing in total to support 4 sticks? How high of an increase would be potentially damaging to the system. My specs are below.

Asus 970 Pro Gaming/Aura MOBO
AMD FX-8370 CPU No OC
2 sets of G.SKILL Ripjaws X Series 8GB (2 x 4GB) 240-Pin DDR3 SDRAM DDR3 2133 (PC3 17000) Desktop Memory Model F3-2133C9D-8GXL

 

[CountMike]

FX processors have problem when both IMCs are used for 4 slots filled with memory and over 1600MHz.

 

[queueball]

FX processors have problem when both IMCs are used for 4 slots filled with memory over 1600MHz.

Thus far it has been very happy at 1866 with 11-11-11-28 timings.
Stock timings at 2133 is 9-11-11-31. Do you think I could tighten those up? I don't know if the MOBO/Processor would effect the timings or if I can run it as long as the RAM can do it.