Sandy Bridge HD 3000 ReservedMemory "patch" is useless

[ubihazard]

As a follow up to this issue.

The "HD3000: IGPU memory corruption errata" in OpenCore config.plist does not, in fact, do anything. Specifically, we are talking about this quirk under UEFI\ReservedMemory:

      <dict>
        <key>Address</key>
        <integer>268435456</integer>
        <key>Comment</key>
        <string>HD3000: IGPU memory corruption errata</string>
        <key>Enabled</key>
        <false/>
        <key>Size</key>
        <integer>268435456</integer>
        <key>Type</key>
        <string>Reserved</string>
      </dict>

The linked acidanthera bug tracker issue explains the actual solution to HD 3000 graphical issues in detail.

This is a separate issue with the Dortania guide where the wording for Sandy Bridge part of the guide in the ReservedMemory section has to be corrected:

"Used for exempting certain memory regions from OSes to use, mainly relevant for Sandy Bridge iGPUs or systems with faulty memory. Use of this quirk is not covered in this guide"

Suggested paragraph:

"Used for exempting certain (bad) memory regions from being used by the OS, mainly relevant for systems with faulty memory. Use of this quirk is not covered in this guide."

This also closes #234.

[ShroomKing]

Is there a solution that can work for other laptops?

I have a T420 thinkpad that has this problem. But afaik i’m not using the fan reset patch, do you know if there’s anything else i can try to reduce writes to EC?