With the introduction of Intel's 8th generation Core processor line (Coffee Lake), Intel also announced a new motherboard chipset, Z370. The real surprise, however, came when it was revealed that Coffee Lake would not be compatible with Z270 motherboards even though they use the same LGA 1151 socket. Some people assumed it was an arbitrary restriction, but it might have to do with Intel planning to release 8-core Coffee Lake chips sometime down the line.
Andrew Wu, product manager for Republic of Gamers (ROG) motherboards at Asus, spoke with Bit-Tech about the new CPUs and what is going on with backwards compatibility. When asked to shed some light on the technical details preventing Coffee Lake processors from working in Z270 motherboards, Wu responded that it was "Intel's decision," suggesting that compatibility could exist if Intel allowed it.
Bit-Tech prodded further, asking Wu if it was a physical limitation, as Intel claims the restriction has to do with power delivery.
"Not really. It [the power delivery] makes a little bit of difference, but not much," Wu said. He added that it would be possible to support the current crop of Coffee Lake processors in a Z270 motherboard with "an upgrade form the ME [Management Engine] and a BIOS update," except that "Intel somehow has locked the compatibility."
Now here's where things get interesting. For Coffee Lake, Intel added more pins to provide more power to the new CPUs. While Wu believes that current 6-core Coffee Lake processors could work in Z270 motherboards if Intel allowed it, he concedes "It's possible that these are in preparation for the high-core count processors."
In other words, while Z270 motherboards might be able to handle the jump to 6-core, things could get tricky when and if Intel introduces 8-core SKUs. If that is the case, then Intel erred on the side of caution by restricting Coffee Lake on Z270 motherboards altogether, rather than supporting Coffee Lake up to 6 cores, and requiring Z370 for 8-core CPUs.
Of course, this is all speculation at the moment. However, with AMD pushing out 8-core CPUs to the mainstream market with Ryzen, it wouldn't surprise us if Intel followed suit in the not-too-distant future.
Either way, Wu doesn't see the situation as a bad one for customers.
"Usually, the kind of customers that already have a Z270 board will probably not upgrade for this generation. For the majority of Z370 users, maybe they have been using their PC for three or five years, so these are still good products for them to upgrade to," Wu said.