laptop slow after installing Spectre/Meltdown mitigations
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I have some pretty low end AMD A9 9420 based laptops that are less than one year old - don't ask, my own fault I know...
They are HP Probook 455 G5
They have performance worse than 8+ year old laptops after Spectre/Meltdown mitigations are installed. They are essentially useless.
I'm trying to disable the mitigations - they aren't as much a worry for desktop machines as they are for VM hosts, even though they can be exploited by browser based malware/scripts.
It seems like the following two registry changes will disable the disablable mitigations:
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 /freg keys pulled from
https://support.microsoft.com/en-us/help/4073119/protect-against-speculative-execution-side-channel-vulnerabilities-in -
https://www.grc.com/inspectre.htm
Shows mitigation status and allows you to modify the reg settings
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@notverypunny said in laptop slow after installing Spectre/Meltdown mitigations:
https://www.grc.com/inspectre.htm
Shows mitigation status and allows you to modify the reg settings
LOL - I considered posting that too - I looked at it - but in my case, it wasn't giving me any option for disabling Meltdown, only Spectre. Now that could be because on AMD A9 hardware I might not be able to disable Meltdown mitigation.
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@Dashrender said in laptop slow after installing Spectre/Meltdown mitigations:
@notverypunny said in laptop slow after installing Spectre/Meltdown mitigations:
https://www.grc.com/inspectre.htm
Shows mitigation status and allows you to modify the reg settings
LOL - I considered posting that too - I looked at it - but in my case, it wasn't giving me any option for disabling Meltdown, only Spectre. Now that could be because on AMD A9 hardware I might not be able to disable Meltdown mitigation.
Ahh... I don't suppose there's an option to flip them to Linux? We don't have anything AMD with the exception of a few ancient machines so I can't check.
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@notverypunny said in laptop slow after installing Spectre/Meltdown mitigations:
@Dashrender said in laptop slow after installing Spectre/Meltdown mitigations:
@notverypunny said in laptop slow after installing Spectre/Meltdown mitigations:
https://www.grc.com/inspectre.htm
Shows mitigation status and allows you to modify the reg settings
LOL - I considered posting that too - I looked at it - but in my case, it wasn't giving me any option for disabling Meltdown, only Spectre. Now that could be because on AMD A9 hardware I might not be able to disable Meltdown mitigation.
Ahh... I don't suppose there's an option to flip them to Linux? We don't have anything AMD with the exception of a few ancient machines so I can't check.
I'd be surprised if there wasn't a way to disable them in Linux.
But I'm not looking into that at this time. -
I've applied these MS supplied registry changes for disabling both Spectre and Meltdown, and GRC's tool still reads Meltdown as Protected: YES. ug! Of course, who knows if the utility can really read this right...
When both Spectre and Meltdown were listed as protected: Yes - it said Performance: GOOD - which is a damned lie!
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Wasn't the bios also involved in these mitigations?
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@Pete-S said in laptop slow after installing Spectre/Meltdown mitigations:
Wasn't the bios also involved in these mitigations?
In so much as a micro-code patches for the processors are concerned - yes. My processor is updated to the most current, Oct 2019. Doesn't matter - performance still sucks!
I applied these reg changes, rebooted - then applied a script I've done many times before. It was amazing how slow the script ran compared to other machines. I took a video, I'll see about posting it later.
