DIMM works only in non-standard slots

[mhp]

New build:
MSI Z170A PC MATE BIOS A.9 (2016-05-24)
EVGA SuperNOVA 750 G2 80+ GOLD, 750W
Intel Core i7-6700K 8M
G.SKILL Ripjaws V Series 16GB (2 x 8GB) F4-3200C16D-16GVS

According to the support page from G.SKill http://www.gskill.com/en/product/f4-3200c16d-16gvs,
the memory and the MB are compatible.

Following MB instructions, I inserted the memory in slots 2 and 4,
but it would not post. The LED on the board indicated DIMM problem.

I inserted only one DIMM in each of the 4 slots until the MB booted to BIOS screen.
With DIMM in slot 3, Bios reported memory is running at 2133 MHZ at 1.2v.
At this point, with only one stick in slot 3, I updated the MB BIOS to A.9.
Enabled XMP and rebooted.

With DIMM in slot 3, Bios reported memory is running at 3200 MHZ.

I rebooted with memory in slots 2 and 4.
Same problem: The LED on the board indicated DIMM problem.

After trying all possible permutations,
I could boot to bios with DIMMs in slots 3 and 4 running at 3200 MHZ.
Installing Windows 10 and running various memory tests, the system passed all tests.


The MB guide says DIMMs should be in slots 2 and 4.
But I could get to work only with DIMMs in slots 3 and 4.
My concern is if this would not lead into problems further down the line.
For example, when I upgrade to 32 GB in a year or 2 from now.

[GSKILL TECH]

It will most likely lead to problems so it is great you brought it up now instead of later.

3 and 4 means single channel, so it may be the B channel is good, while A is defective. The only way to know for sure is to test with other RAM. Also, double check CPU, CPU socket pins, and CPU cooler installation. A simple over sight can cause such a problem, so it is always best to double check.

[GObonzo]

@ mhp,
had this same problem with dual channel not working due to CPU issue. all DIMM slots and all RAM sticks worked fine in single channel setups but any attempt at dual channel would lead to the system not posting.

went through rather expensive return shipping trying to RMA the motherboard, passed all tests and was returned.
tested my RAM in multiple other boards, turned out fine in both single and dual channel.
finally got my hands on a second Z97 board to test the CPU; same exact issue with the CPU not being able to handle any form of dual channel memory configuration.

have had a bit of trouble getting Intel to respond about an RMA.