Probook 455 G4 and Microsoft June Cumulative Update (KB4284835) - Internet performance tanked

[JohnClicquot]

Thanks Jtrout!

It turns out deleting them does not solve it. and changing the values to 3 does!

I was very close to uninstalling al updates again.

The Spectre tool now also gives a red NO! for spectre protected.

[jtrout]

Microsoft released an update advisory last night that finally addresses our issue at -

https://portal.msrc.microsoft.com/en-us/security-guidance/advisory/ADV180002 (FAQ #18)

I tried out the setting of "1" for the FeatureSettingsOverride entry as they suggested.  Running fine.  Maybe a slight performance degradation, but it's livable and as expected with these mitigations.

1. I have an AMD-based device and I am experiencing high CPU utilization after installing the June or July Windows security updates or after installing a BIOS update for my device. Is this expected?

There have been reports of high CPU utilization resulting in performance degradation on some systems with Family 15h & 16h AMD processors after installing June 2018 or July 2018 Windows updates from Microsoft and updated AMD microcode that addresses Spectre Variant 2 (CVE-2017-5715 - Branch Target Injection). AMD and Microsoft have investigated this issue, and Microsoft is working to provide a solution in the near-term. This advisory will be updated when a solution is released.

Customers who wish to remediate the performance impact caused by this issue may wish to consider temporarily disabling Spectre Variant 2 mitigations via registry settings for Windows until a solution for this issue is released. When a solution is released for this issue, customers will need to re-enable the registry settings.

We do not recommend that customers uninstall the June or July security updates for Windows because the June and July updates provide numerous other critical security fixes.

Changing Registry Settings

Important This section, method, or task contains steps that tell you how to modify the registry. However, serious problems might occur if you modify the registry incorrectly. Therefore, make sure that you follow these steps carefully. For added protection, back up the registry before you modify it. Then, you can restore the registry if a problem occurs. For more information about how to back up and restore the registry, see [Microsoft Knowledge Base article 322756[(https://support.microsoft.com/en-us/help/322756).

Note Disabling and enabling the Spectre Variant 2 mitigation through registry setting changes requires administrative rights and a restart.

To disable Spectre Variant 2 mitigations:

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 1 /f

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 3 /f

Restart the computer for the changes to take effect.

When the solution is available, the registry keys will need to be re-enabled.

To enable Spectre Variant 2 mitigations:

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverride /t REG_DWORD /d 0 /f

reg add "HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management" /v FeatureSettingsOverrideMask /t REG_DWORD /d 3 /f

Restart the computer for the changes to take effect.

[jtrout]

Latest cumulative update for August finally addresses the problem.  From Microsoft's KB on the update -

Addresses an issue that causes high CPU usage that results in performance degradation on some systems with Family 15h and 16h AMD processors. This issue occurs after installing the June 2018 or July 2018 Windows updates from Microsoft and the AMD microcode updates that address Spectre Variant 2 (CVE-2017-5715 – Branch Target Injection).

We are back to normal operation as of the August update.  Finally!

(Be sure and delete the registry keys if you created them before installing, no need for disabling mitigations at this time any longer)

[jtrout]

One last update on this post.  The fix is only contained in the August 2018 Cumulative Updates for Windows 10 Versions 1709 and 1803.

If you are still running  a Windows 10 version before 1709, either update to a later version or keep using the registry hack.

Just tried the update on a 1703 client, and the speed issue is still there.  Will be looking to move them to 1803 to avoid the headache.

[JohnClicquot]

I just want to say that I really like that it is fixed.

I can love my laptop again 😉 and its snappiness!

Thanks everyone for your contribution!