TridentZ RGB on Maximus X Formula

[CanesVenetici]

Hi

Been having some issues related to stability. My setup is:

Seasonic Prime 1000w 80+ Titanium
Asus Maximus X Formula
8700k
Gskill TridentZ RGB F4-3600C17Q-32GTZR
2 r9290x's (soon to be replaced with 2 1080 Ti's)
Samsung 500 Gb 940 Pro as a system drive

Enabling the xmp profile will let me boot into windows but it's not stable. I've tried bumping the dimm voltage up from the base 1.35 and it doesn't seem to matter.
This kit is listed on Asus's qvl, but I can't find anything on gskill's sight even relating to coffee lake. Did I waste my money getting this kit?
Running memtest86+ v7.5 with the default xmp settings I'm getting errors out the wazoo on test 13, the hammer test. If I slow it down, to say 3200, it'll pass just fine.
So is my ddr bad? Weak memory controller in my cpu? Not enough juice? I'm kind of at a loss at the moment.
Would I be better off lowering to say 3200-3400 and trying for tighter timings or a 1t command?
Right now I'm kind of at a stand still and I'm not sure what to do. Any help is greatly appreciated.

[emissary42]

Do you only get memtest errors in hammer test? This test does not test for module failure but a certain vulnerability (rowhammer exploit, see memtest86 FAQ) and the result in general shouldn't affect everyday stability for a non-infected system.

Please make sure that you decline the turbo enhancement pop-up when enabling the XMP, because with that the board will overclock your CPU. You might also want to try Maximus Tweak Mode 1 or Mode 2 instead of AUTO. The setting does influence how the board handles the secondary timings and if it actually uses the ones from the XMP or not.