Specter/Meltdown performance impact on my Lenovo T450S

Did some quick benchmarks tonight with the mitigation’s enabled and disabled.

I’m losing over 10% performance on a Broadwell i5-5300U

 

Enabled:

 

Disabled:

If you want to try yourself here is how you can disable the mitigation’s. Run the following from Command Prompt or PowerShell. Make sure you ‘Run as Administrator’.

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

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

Once you’ve changed these registry keys reboot your PC.

This is obviously not recommended for production as you’re disabling important security updates on your system.

To re-enable the protections run the following:

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

 

Source: https://support.microsoft.com/en-ca/help/4072698/windows-server-guidance-to-protect-against-the-speculative-execution

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