After seeing the recent success about using the Quad Core Coffee Lake in Skylake/Kaby Lake generation Motherboards and viceversa, I just remembered that there are other very close relatives which may be possible to get working, too. I’m talking about the Xeon E3 1200v5 (Skylake) series, the Xeon E3 1200v6 (Kaby Lake) series, both of these for LGA 1151 and identical to their Core i5/i7 Desktop counterparts, and as something very ambitious, the Xeon W 2100 (Skylake-E) series for LGA 2066, which should use a mix of LCC (Low Core Count) and HCC (High Core Count) parts as the HEDT Core i7/i9 counterparts.
As some people may know, Intel uses the very same dies and Sockets (LGA 1155/1150/1151) for both their mainstream consumer products (Celeron/Pentium/Core i3/i5/i7) and their entry level Workstation/Server line (Xeon E3 1200). A similar relationship happens between the Core i7 HEDT line and their Xeon E5 1600 counterparts in LGA 2011/2011-3 in a higher market segment. The main difference between the two is that the Xeons supports using ECC Memory Modules if you also paired them with the Intel C series Chipsets. Xeons E3, being based on the consumer dies, also have an integrated GPU, which is supposed to use certified Drivers that make them to be supported by some professional applications (Similar to GeForce vs Quadro and Radeon vs FirePro). Amusingly enough, ECC was actually supported in many Dual Core Core i3 models, and if I recall correctly, even on Pentiums, but Intel disabled it on all Quad Core Ci5/Ci7 parts, perhaps because they never really bothered with a Dual Core Xeon E3 lineup and decided to just leave ECC available on the low end models.
Regardless these details, the thing that made the Xeons E3 interesing was that there were a few SKUs that had better specifications than a similarly priced Ci5/Ci7 counterpart, like the Xeon E3 1245v3 (Haswell) that I have for which I paid a bit less the same than a Core i7 4770, and you could use them in standard consumer Motherboards if you wanted to. Some people liked the Xeons E3 models without integrated GPU because they were slighty cheaper, but I always though than it was a bad idea to miss half of the Processor die to save 20-30 U$D, albeit they were the cheapest possible 4C/8T models. Anyways, Intel eventually noticed that some users were purchasing Xeons E3 to use as Core i5/i7 replacements, and, since Skylake, they began to restrict them to only be able to work in C series Chipsets. Thus, Xeons E3 1200v5 shouldn’t POST with standard Desktop Chipsets like Z170 or Z270, only in C232 and C236. Also, Intel didn’t refreshed the Chipsets for Kaby Lake, so the 1200v6 line uses these two, too. After seeing what current modders have achieved, I think that getting the later generations of Xeons E3 to work in standard LGA 1151 Motherboards (Be it Skylake/Kaby Lake or Coffee Lake) should be within the realm of the possible. However, this is not actually very interesing because Xeons E3 got crushed in the price-specification relationship after Intel released the Coffee Lake consumer line with affordable Quad Cores thanks to AMD becoming competitive again, and neglected touching the Xeons E3 prices, so no one would buy a Xeon E3 for a consumer platform. Is not as amazing as getting a Core i3 8100 working in a cheap H110 Motherboard.
So, what is interesing? LGA 2066. Repeating roughly the same things that were said previously, we have a very similar scenario: Xeon W has some interesing SKUs, but they are supposed to run only in C422 based Motherboards, not X299. In general, the Xeons W of this generation pretty much absolutely sucks because Intel released them at a MUCH HIGHER PRICE that their Ci7/Ci9 HEDT counterparts, so compared to previous generations, I wouldn’t pay an extra 300 U$D just for the Xeon brand name if it was not going to use ECC, so at first sight they are not as interesing as previous generations Xeons E5 1600 could be for non-overclockers. However, there is a model, the Xeon W 2102, that could be an impressive wonder. For 200 U$D, it uses a Skylake LCC die instead of Kaby Lake-X, has ECC support, and the full 48 PCIe Lanes (Ci9 for some reason uses 44 instead of 48). Albeit it is a humble 2.9 GHz 4C part with no HT or Turbo, it looks like an I/O beast. Sadly, missing consumer Motherboards greatly limits your options, yet based on the modding community breakthroughs, I want to think that it could be possible, too.
I’l leave getting Xeons working as an idea, if someone thinks that it is worth to look into.
I have an Asus Q170M-C next to me, that is running with a Xeon E3-1235L V5, as I type this message.
However, I cannot tell you, at the moment at least, if it would run with stock BIOS, too.
Currently the BIOS has disabled ME and is also otherwise slightly modded.
According to the CPU Support List of your Motherboard, it doesn’t support Xeons. Here is the CPU Support List of the ASUS P10S WS Motherboard, which is C236 based, and does explicitly mention them.
Can you go into full details of what did you exactly did with your Motherboard Firmware to get it working with that Processor? Did you modded and flashed the Firmware with another Processor before testing the Xeon?
ME can block booting with ‘unauthorized’ CPUs. What you can try is applying ME_cleaner on your BIOS and flash that modded BIOS.
Gigabyte is out, as they are not supported by ME_cleaner. You can try with any of Asus, Asrock, MSI as long as you can flash the BIOS externally.
Ideally when the ME is out, it should allow booting with Xeons as Microcode should be included already. Disabling ME on version 11.8 also managed to boot the CFL mod, although this is still highly experimental.
"bankkopf" was faster. 
I cannot really provide too many details, of what makes it work, as I did not expect it to work, right away.
Had ordered the Xeon for testing purposes, as I thought it should somehow work.
Already had disabled ME via ME_cleaner before.
Just a quick update:
Same Xeon E3-1235L V5 CPU is working fine in a Fujitsu D3402-B2, too. Also with pre-disabled ME. Just put it in and booted right up with no issues.
I would assume that it would also work with other chipsets.
I’m working on disabling the ME on Asus C422 board but has not got any luck so far. The board would not flash the ME no matter what software I use. I tried EZ flash, it doesn’t recognized the file(of course), then AFU EFI, Intel FPT and FWUpdate. It just wouldn’t take the modified BIOS file. Right now I’m planning to use a external flasher. Will update if I get any positive result. But I guess this is not a interesting topic to most people as Xeon W processors are so hard to acquire.
A bit late, but did you managed to get it working?
@celemine1gig Could you help? I did Me_Cleaner,in BIOS the ME version is 0.0.0.0 but with the E3 1270v5 it wont boot. Pc turn on and shuts off right after. I did two other BIOS, one with the AltMeDisable bit set and another with Me_Cleaner and AltMeDisable bit set, both didn’t work, start and shut off and keep it doing that. My mobo is an Asrock z170a x1/3.1.