Windows 10 Spectre and Meltdown Mitigation

Hellbovine

Active Member
Some time ago there was a vulnerability identified as "Spectre" and "Meltdown" that was patched in Windows.

The "problem" with Microsoft's fix, is that they patched the OS with a temporary workaround that decreases CPU performance. The long term solution to mitigate these vulnerabilities is with updated CPUs, which is something that Intel/AMD are working on.

Well if you are using older hardware the OS patch may not be worth having for power users and gamers, since it comes at a cost in performance.

In order to disable this patch on INTEL CPU within Windows you simply add the following registry keys:

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Session Manager\Memory Management]
"FeatureSettingsOverrideMask"=dword:00000003
"FeatureSettingsOverride"=dword:00000003

However, I'm not certain on how to properly disable the patch on AMD CPUs. The information on the internet seems to be contradictory, plus also confusing too. So I tested it out myself for the Intel one and confirmed that it is working with the keys I put above. But since I do not have an AMD CPU I cannot manually test that one.

Would any of you with an AMD CPU please test this out and post your findings? It's really quite easy, I'll explain the process, it takes about 5 minutes in total:

1) Download a registry comparison tool such as "RegistryChangesView" by Nirsoft. They have portable versions that do not need to install.

2) Download "InSpectre" by GRC (Gibson Research Corporation), it is portable and doesn't need to install.

3) Run the RegistryChangesView tool (in admin mode), and create a registry snapshot.

4) Run the InSpectre tool (in admin mode) and click the two options at the bottom, "Disable Meltdown Protection" and "Disable Spectre Protection".

5) Now press "OK" inside the RegistryChangesView to get an "after" shot of your registry and it will show you 1 or 2 keys, probably the exact same keys I wrote above, but they will have different dword values.

That InSpectre tool also gives you a full rundown on more information about what these vulnerabilities are so you can learn more if you're interested.
 
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Hellbovine

Active Member
Also, disclaimer here about security issues by disabling, blah blah blah. Don't mess with it if you don't know what you are doing or if you don't have safe internet habits.

You can immediately enable the protections again using the InSpectre tool as well, fyi.
 
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Also, disclaimer here about security issues by disabling, blah blah blah. Don't mess with it if you don't know what you are doing or if you don't have safe internet habits.

You can immediately enable the protections again using the InSpectre tool as well, fyi.
Hello. On my old AMD processor, both options are not active.
 

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Hellbovine

Active Member
Hrm, that's really odd. This is exactly why I wanted to manually have it tested, because it didn't feel right going by the articles. So in your case the options are not only greyed out, but Spectre is defaulted to disabled, and Meltdown is defaulted to enabled.

I'm not quite sure what to make of this. Anyone know how to troubleshoot further for AMD CPUs?
 
Oh, did you run InSpectre in admin mode? Maybe that's why it's greyed out.
Yes of course in administrator mode. I downloaded the program from the official site, the latest version. The program shows that there are no performance problems. If you believe the test program, then not all AMD processors need a fix.
 
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Hellbovine

Active Member
You'll have to help me please on how to install the SpeculationControl, I'm not a powershell user, everything I've ever needed to do over the years I could do from command line, so I never needed to learn PS. My PC is offline, if I download the file using the manual link, how do I install it and then run it?

Edit: Oh, nvm powershell instructions are at the very end of the tenforums link.
 
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