Finally Intel does not block the backward compatibility of the Coffee Lake and Kaby Lake / Skylake, the problem is in the pins, the Coffee Lake uses extra power pins with respect to the sixth and seventh generation processors.
We have witnessed many complaints and protests from users regarding the new Intel processors and the inherent need to buy a new motherboard for the Coffee Lake processors. Kaby Lake / Skylake is not compatible with Coffee Lake and vice versa and the reason is the amount of extra cores in the new Intel processors. Specifically, Intel has introduced more VSS (negative) and VCC (positive) pins in the eighth generation processors, so this modification makes compatibility between the sixth and seventh generation impossible, with this eighth generation.
They have gone from 377 VSS in sixth and seventh generation to 391 VSS in the ninth generation and from 128 VDC in the two previous generations to 146 VDC in this new generation, and thus the RSVD pins (reserved), go from 46 to 25. Intel has been forced to this modification in the LGA 1151 socket for Z370 motherboards, due to the amount of extra cores, since it needed to power it and with the available power supply, that was not viable. It is true that explaining this from the beginning or renaming the socket LGA 1151v2, the problems would have ended.
We do not know who is responsible for the marketing or press strategy, but hey, I would have had to talk to the development team and explain this before, we would have avoided assumptions, failed attempts to install with Coffee Lake on a Kaby motherboard Lake (which by the way, they want to risk the integrity of the processor). Knowing this, the need for a new motherboard is understood, although, was it necessary to launch the Kaby Lake and the Coffee Lake the same year?
Source: wccftech
I wonder how they did to keep the bus speed and the pci lines with fewer pins
Very good question. I also have that doubt
Well, it is explained. Sockets had a series of reserved pins or what is the same, without a specific function and now they have a specific function, which is power. There's no more.
If I saw it. They had something mad of 40 pins. Now they have about 20 pins.
Thank you, I understood, although for me it is something silly to have 20 pins without using it, perhaps it is due to manufacturing issues