DMI 2.0 vs 3.0

[variab1e]

In my limited understand, DMI is the interconnect between the CPU and the southboard / PCH. 2GB/s in 2.0 vs 3.93 GB/s in 3.0. x4 links for both. These mapping perfectly to the link/channel speeds for PCI-E 2.0 and 3.0 respectively in an x4 configuration. Thus the CPU has a PCI-E 2.0x4 or 3.0x4 connectionion to the PCH. So I suppose two questions...

1) In a processor such as the i7-68xxk through i7-69xxk , where an LGA2011v3 and thus X99 chipset is used, utilizing DMI 2.0 , is there going to be any performance difference between this and a more "modern" processor architecture such as the Skylake based i7-6700k / z170 with DMI 3.0?

2) As a key bit of information that I assumed... DMI is merely the connection to the PCH, and in any X99 motherboard all devices & connections except ( the PCI-E x1 slots ) have their own direct PCI-E channel to the CPU which doesn't utilize DMI at all? So the USB 3.1 , the PCI-E x16 slot, the m.2, LAN, etc... is all direct PCI-E?

If this is true the only way DMI would change performance is if I was utilizing all of the PCI-E x1 ports correct?

 

[mv2devnull]

2. No. All the peripherals are connected via the PCH and only some (larger) PCIe slot(s) are directly connected to the CPU.
See http://images.anandtech.com/doci/9730/Chipset Config.png

 

[Insert_Nickname]

1) Of course. But it's only bandwidth that's limited. There is a very, very small latency penalty for PCH connected devices, versus direct-to-CPU connections, but its so small as to be virtually undetectable.

2) On the LGA-115x platform, you'll most often see additional controllers and slots wired to the PCH. There are a few exceptions, the most obvious being the Asrock Z97 Extreme6 with its "Ultra M.2" slot wired into the CPU. The X79/X99 HEDT platform is a different matter, see below.

2. No. All the peripherals are connected via the PCH and only some (larger) PCIe slot(s) are directly connected to the CPU.

Correct, but do be aware that some X99 boards have peripheral connections and devices directly wired to the CPU, since the X99 PCH does not support PCIe 3.0.