Dear fellow bios moders
I have tried for a few days now to get through the code 19 error of my Asus X99 Sabertooth. Like most people with this problem I can boot to the bios by resetting the bios. But I have found out, that whenever the cpu is removed and inserted again I can boot without resetting. That makes it possible to change some bios settings, but nothing I have done seems to help. I have tried to change the input voltage, that reads 1.776 on auto, to 1.82 as is stated as the nominel voltage at the Intel ark homepage. But it doesn’t seem to help.
The reason I can’t let this error go and move on, is that I can boot by reseating the cpu, as if nothing is wrong. So it seems so close.
I have then compared the Asrock Taichi bios file and the latest 4101 Sabertooth X99 bios file in the UEFITool. A lot of the pei boot sequence seems to be the same, except from the modules OCMR_PEI (Maybe OverClock ManageR?) the Memory_OK_PEI and the EpuHwModePei (The special asus hardware chip that controls power delivery?)
I have tried to delete these modules without luck, but the error code changed to 55, that should be related to memory (maybe memory overclock error?) so something did at least change.
I have even tried to replace the CpuMpPei module with the one from the Asrock Taichi X99, but it lead to a boot loop with about ten seconds of uptime.
The combination of modules to replace, delete or alter seems endless so I decided to get some expert advice before I go completely crazy 
I hope someone (maybe @100PIER ) can shed some light on this, at least just to find the root of the problem. I really want to crack this nut!
@Chocmoo
I have an Intel Core i7-5930K installed on my X99 Sabertooth.
BIOS installed: v4101 7oct19, with µCode CPU up to date (UBU Tool):
[[File:µCodes_06mai19.PNG|none|auto]]
I never got and observed the code error 19 when booting:
Bios settings for ‘INT19 Trap Response’ option = “Immediate”.
Here the Spectre test result which does provide me the more stable and performance:
[[File:InspectreTest_01apr20.PNG|none|auto]]
I have not modded any CPU BIOS settings and let only automatic settings done via BIOS F11 key light overclock so that reported via HWINFO64:
[[File:HWINFO64_01apr20.PNG|none|auto]]
You do seem to use an CPU Engineering Sample version, does is it fully BIOS supported ?
Does the problem become abruptly ?
Thank you for you quick reply.
Yes it is an ES and therefore not officially supported by anyone. Is seems to be a common problem with Asus X99 motherboards that they act this way with Xeon E5 v4 ES.
I guess that Asus is a little more picky with their CPU specs than EVGA, Asrock and MSI that I read somewhere else will work with these ES cpus.
I hope the community can help out with some kind of modding. Do you know anyone in the forum that have tinkered with bios modules through UEFITool?
I “Think” for this kind of issue on these boards, you remove all CPU microcodes, there is a huge thread about this over at Anandtech - https://forums.anandtech.com/threads/wha…-xeons.2496647/
But, that may be dealing with totally different issue. You did mod BIOS, or confirm, that your BIOS has microcode for this CPUID in it correct? If yes, it’s there, then we know missing microcode isn’t the issue at least.
Did you test early BIOS, like first 1-3 BIOS, which you still may or may not have to add back in ES microcodes.