Intel’s 8th-generation Coffee Lake desktop chips might have upped the core count and include “the best gaming CPU ever,” but it was disappointing to learn that they are only compatible with new 300-series motherboards. It appears, however, that with a little tinkering it's possible to get some of these processors working on both 200-series and 100-series chipset mobos.
Even though they use the same LGA 1151 socket that’s been around since Skylake launched in 2015, Intel says its Coffee Lake chips are not compatible with 200/100-series motherboards. The company said this is because of more pins being allocated for power delivery, which is a requirement due to the six-core configurations.
But over on the Win-Raid forums, rootuser123, LittleHill, dsanke, elisw, Mov AX, and 0xDEAD managed to prove Intel wrong by getting a Coffee Lake chip to run on both 200-series and even 100-series boards.
By adding the Coffee Lake CPU’s microcode, the iGPU's UEFI GOP driver, and some Management Engine bootstraps on the side of the motherboard BIOS, the modders had an 8th-gen chip running stable on the older platforms.
While this is an incredibly impressive feat, it's worth noting that the team was using a four core/four thread i3-8100 chip in its tests, rather than any of the six-core models. In the accompanying guide, they recommend not using the mod with i5 and i7 K-series CPUs because of the higher power limits, but it might still work with the non-K versions of these chips.
Back in December, a Chinese user got his Core i3-8350K processor to work on a Z170 motherboard, though it did cause a few issues.
Remeber to check out the Win-Raid forum, which contains guides, patches, and the initial think tank thread. Just make sure you know what you’re doing and understand the risks involved if you decide to try it.
https://www.techspot.com/news/73549-modders-get-coffee-lake-cpu-running-200100-series.html
