You may have seen that Microsoft has halted distributing security patches related to GPZ Variant 1 (one of the variants of Spectre) due to the update causing some older AMD systems to get into an unbootable state. Wanted to make it clear this patch is to address GPZ Variant 1 (one of the variants of Spectre) and not GPZ Variant 3 (Meltdown).



AMD is aware of an issue with some older generation processors following installation of a Microsoft security update that was published over the weekend. AMD and Microsoft have been working on an update to resolve the issue and expect it to begin rolling out again for these impacted shortly.

Discussion

Source: [H]ardOCP – Microsoft Spectre v1 Patches Borking Older AMD Systems