RAM 4 Modules won't run full speed

[harvey.l12]

My RAM- CMZ8GX3M2A1866C9 (Corsair Vengeance 1866MHz)
My Mother Board- Gigabyte X-97 SOC

I have sticks of RAM now and my system has been running with 2x4GB sticks for nearly a year and i decided t buy 2 more sticks of the exact same RAM to get 16GB (4x4GB)

My first two when running were at 1866MHz which is the standard speed for this RAM. When i added my 2 new sticks in the PC wouldn't boot not even to BIOS. jut black screened. Took the two new ones out and it worked fine then i tested the new two together and they worked etc.

FINALLY got then working but at 1800MHz with all 4 sticks installed but when going to 1866MHz it black screened again and didn't boot.

I have tried...
-Memory voltage from 1.500 up to 1.540 don't want to go any higher.
-Change the timing's and increased them all (bigger number so they are slower) all by 3.
-Looked at other BIOS settings can't find much more myself.

I know 1800 - 1866MHz is a barely noticeable difference but i bought the RAM for the speeds and just wanted to try and get them speeds from all 4 sticks.

Any suggestions or ideas on any other settings i can tweak to get a result?

Thanks for reading!

 

[stulid]

Try adding a touch of voltage to the cpu IMC

 

[harvey.l12]

after i used CMOS the voltage was at 1.267 anyway which is too high for me, so i put it down to 1.150. So even with the 1.267 set the RAM wouldn't work, can't imagine putting it any higher then that would make it work? But i can try if you still think i should.

What do you think i should set it too? Its a i7 4790k

 

[new boy]

What voltage do you mean? Vcore? Don't worry about that.

Try a 0.05v bump on system agent

If that doesn't work, try a 0.15v bump on both digital and analogue io voltages.

EDIT

gigabyte boards use different terminology which I am not familiar with I think. Google the voltages I named and you should be able to find alternative names that match your bios.