CPU A dumb question on 6th gen intel CPUs and PCI-express lanes

[TheInternal]

So... my i7-6700k is in the mail already. However, it occurred to me that the 6700k only has 16x PCI-express lanes.
I plan on slapping the i7-6700k in a Gigabyte GA-Z170N-Gaming 5.

If I put a Samsung 950 Pro SSD (which uses 4x PCI-express lanes), does that mean I'll knock the 6700k down to 12 lanes available for my GPU (looking at the 1080 for this build)? If so, will this limit it's bandwidth / introduce a bottleneck?

I'm planning on doing VR and possibly some 4k gaming with it, so I'm concerned I may have overlooked a potential bottleneck.

 

[TunnelVision]

The processor may have just 16 PCIe 3.0 lanes but the chipset offers additional PCIe lanes (up to 20 of them for Z170) via what they call the DMI 3.0 link to the CPU. The link is equivalent to 4 PCIe 3.0 lanes in terms of speed and is shared with other things.

 

[TheInternal]

But is one of the things it's shared with / likely to impact the GPU?

 

[jeshikat]

The M.2 SSD slot on that Gigabyte runs off the chipset lanes so it won't affect the GPU at all.

 

[|||]

Yep, it won't affect the GPU bandwidth at all and will run off of the PCH. The only ITX board that ran the M.2 off of the CPU PCI-e lanes and cut down on GPU bandwidth was the Asus Maximus VII Impact. BTW, the hierarchical structure of PCI-e controllers means that it gets knocked down to x8, as you can only have x1, x2, x4, x8, x16, and x32 configurations, according to the standard.

Technically DMI is physcially the same as PCI-e, it just runs an extended protocol that the processor and PCH understand.