GA-Z87X-OC + 8Gb G.SKILL F3-17000CL8D-4GBXMD OCCT error after 2-5 minutes

[failure13]

Hi guys, really need help here!
Just bought this great motherboard GA-Z87X-OC and new CPU i7-4770K!
I'm utterly new to Z87 overclocking / memory stabilization.

My goal is to achieve default processor clocks with it's default x35 uncore, and run 8Gb of my memory on it's XMP specs, which are:
G.SKILL F3-17000CL8D-4GBXMD, 2133mHz, 8 9 8 24, 1.65V

For now i've tried everything about CPU and voltages set on auto (ie optimized defaults), but i've disabled all C states, disabled intel thermal monitor, and enabled EIST.
When i try to set manually memory like set 2133mHz, 8 9 8 24 2T timings, and voltage exactly to 1.65V (it shows value a bit higher on sensor, like +0.2V to what you set in bios, maybe it's the problem?) - i got error in OCCT after 2-3 minutes (64bit, 8 threads large data set)

I also tried to leave CPU as is, and just set memroy to XMP, have run the same test - same error arise after 3-5 minutes.

My guess is that there should be something that should be set maunally, like QPI/VTT in X58 motherboards and i7-970.
Could you please point some voltages like that i could try, explain what exactly they are, and how they will affect temps?

P.S Temps for this CPU seem to be utterly fine, 64 at it's max. I use Corsair CWCH90 watercooler.
P.P.S. I'm absolutely sure that RAM is working, have used it for years on X58 and tested via ramtest multiple times.

So please gskill support, help me troubleshoot / understand as fast as you can, coz if something is wrong with CPU or motherboard, i must RMA it asap!

[failure13]

Could it be overheat of RAM itself maybe?
I use 4 modules without cooler now, should i try with cooler?

When i touch RAM stick under load, they doesn't seem to much heat, something like 40 at max i guess...

[Tradesman]

SO you are in effect using 2 sets of the DRAM? If so can try raising the VCCSA + 0.10 and DRAM voltage + 0.50, and give that a try, it's never a good idea to mix sets of DRAM, even of the same exact model - a 4 stick set cost a little more - but that's because all 4 sticks are tested to work together, and XMP is programmed by the packaged set, 4 sticks takes different advanced/secondary timings than does a two stick set, so chances good theose timings need adjusting also

[failure13]

Tradesman
I know i know, but that's actually your fault
I mean, in Russia amount of good quality g.skill memory is close to 0.
I would love to buy 2800-3000 4 stick kits, but no, there are non in here.

Hope you could make it some day, coz the only option is Corsair if you want to go higher than 2400.
And buying such sensitive hardware not in your own country is....let's say a little bit freaky

Anyway, will try your advice, thank you!
And could you explain what exactly is VCCSA?

[Tradesman]

VCCSA is System Agent Voltage, it controls the base voltage through out the system (basically)