[Bug 1748543] Re: intel-microcode when installed on an i7-6850k based system running Artful breaks overclock

[Henrique de Moraes Holschuh]

>From reports elsewhere in the Internet, made by Microsoft Windows users
with KB4100347 installed. Behavior in Linux might be slightly different.

* Several motherboard vendors affected (at least ASUS, EVGA);
* Motherboards based on X99 with overclocking features available through vendor UEFI/BIOS;
* RAM and uncore overclocking not affected by this issue (overclocked values are preserved);
* CPU voltage not affected (changed voltage set points are preserved).

Processors reported as affected:
Intel 6800k, 5930k, 6900k, 6950x, Xeon (no data about xeon models, assume socket-compatible with X99 chipset).

Reports imply the microcode update itself is the problem, not the
updated microcode:  Motherboards whose UEFI/BIOS already has the latest
microcode revision are *not* affected by this issue, and overclock as
expected.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to intel-microcode in Ubuntu.
https://bugs.launchpad.net/bugs/1748543

Title:
  intel-microcode when installed on an i7-6850k based system running
  Artful breaks overclock

Status in intel-microcode package in Ubuntu:
  New

Bug description:
  I have an I7-6850k machine Asus X99-A motherboard, 128GB memory with
  Artful 17.10 installed.  The official clock speed of this processor is
  3.6 Ghz, I have it clocked at 4.3 Ghz, however, if I install the
  intel-microcode package, the machine ignores the BIOS settings and
  reverts to 3.6 Ghz.  Since this package is necessary from a security
  perspective I'm stuck with either being insecure or losing an enormous
  amount of performance.

  ProblemType: Bug
  DistroRelease: Ubuntu 17.10
  Package: intel-microcode (not installed)
  ProcVersionSignature: Ubuntu 4.13.0-32.35-lowlatency 4.13.13
  Uname: Linux 4.13.0-32-lowlatency x86_64
  ApportVersion: 2.20.7-0ubuntu3.7
  Architecture: amd64
  CurrentDesktop: MATE
  Date: Fri Feb  9 13:04:14 2018
  InstallationDate: Installed on 2017-05-05 (280 days ago)
  InstallationMedia: Ubuntu-MATE 17.04 "Zesty Zapus" - Release amd64 (20170412)
  SourcePackage: intel-microcode
  UpgradeStatus: Upgraded to artful on 2017-10-20 (112 days ago)

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/intel-microcode/+bug/1748543/+subscriptions