An odd finding on the X299 Dark Bench Board has the Memory laid out as 2 1 3 4
2 1 CPU 3 4 (But the Real Small Print on the top of each DIMM Slot 1 2 3 4 like in the Image at the Bottom

 
From  Page 34 Support Manual for EVGA X299 Dark (151-SX-E299)
 

But then we have this as well.

Maybe so, I did PM T|n and asked if he could review this Thread.

Still waiting myself...

wmmills
Pretty sure its to have the first ram modules of each group closest to the cpu, obviously for throughput effectiveness and overclocking potential.

Not sure that would make since but also not what the Manuel is telling us or the Bench Board above.
 

wmmills

bcavnaugh

wmmills
Pretty sure its to have the first ram modules of each group closest to the cpu, obviously for throughput effectiveness and overclocking potential.

Not sure that would make since but also not what the Manuel is telling us or the Bench Board above.

You know what, I forgot you guys are dealing with quad channel, not dual so its not a double stick groupings. Ive seen manuals be wrong before but im not sure what other real purpose it could have if not to give you some sort of performance gain, especially on a dark board. Looks like were waiting on Evga on this one! :)

Supports Quad-Skylake-X and 2 DIMM kit for Kaby Lake-X but not really saying what it is in the Manual.
 
Max # of Memory Channels 4 
https://ark.intel.com/products/126695/Intel-Core-i9-7940X-X-series-Processor-19-25M-Cache-up-to-4-30-GHz-
Max # of Memory Channels 2
https://ark.intel.com/products/121499/Intel-Core-i7-7740X-X-series-Processor-8M-Cache-up-to-4-50-GHz- *Discontinued
https://ark.intel.com/products/121500/Intel-Core-i5-7640X-X-series-Processor-6M-Cache-up-to-4-20-GHz- *Discontinued
https://ark.intel.com/compare/126695,121500,121499
 
*Discontinued Seems (Kaby Lake-X Core Series) did not last long

wmmills
No official answer on this yet huh?!?!? Evga is leaving us in the wind here. Curious to know the reason officially.

Nope, Still Waiting.

Closest DIMM to CPU is always numbered first, just like on any other Intel CPU platform.
 
Each side have own memory controller, so order IO > 2 1 >  SKT > 3 4 > 24-pin power side is the correct one.
Since X299 DARK is 1 DPC board, all DIMMs are equivalent anyway when used with SKX CPU.
Kabylake-X CPU have only 2-ch IMC, so DIMM3,4 become DIMM1,2 for it.

TiN_EE
Closest DIMM to CPU is always numbered first, just like on any other Intel CPU platform.
 
Each side have own memory controller, so order IO > 2 1 >  SKT > 3 4 > 24-pin power side is the correct one.
Since X299 DARK is 1 DPC board, all DIMMs are equivalent anyway when used with SKX CPU.
Kabylake-X CPU have only 2-ch IMC, so DIMM3,4 become DIMM1,2 for it.

Thank you, that was the answer I was looking for!