The important part: "After investigating, Microsoft has determined that some AMD chipsets do not conform to the documentation previously provided to Microsoft to develop the Windows operating system mitigations to protect against the chipset vulnerabilities known as Spectre and Meltdown."
Looking for which hardware is affected, I only found a statement form AMD  tldr, Ryzen CPUs are fine
> "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."
Related, I just shared that Microsoft is going to make the mitigations for Windows Server optional item?id=16108356
This should make it very clear that other vendors downplaying the performance impact were misleading users.
Breaking windows is not bricking a machine, can we please stop abusing this term. Brick means irrevocably render an electronic device inoperative (making it as useful as a brick), short of something like JTAG or soldering.
This is especially important surrounding hardware bug concerns like this, because its at least conceivable that interactions with hardware bugs really could brick machines.
EDIT: for posterity post title is "Windows AMD Spectre patches brick some machines" atm.
I had an AMD machine in on Monday that I installed in 2009, was chugging along fine until this update. Now has a stop error on boot.
New machine time - which actually gives Microsoft money in reward for their mistake but is the best course of action for the client.
It’s just expense for the the client and inconvenience for all involved.
Unbootable, they say. I think they actually mean it!
Unbootable, they say. So I think they actually mean it!