The Spectre bug uses what's known as speculative execution, wherein a processor tries to figure out multiple paths that a running program now in the processor cache may take, and predictively loads in what it thinks will be the next line of code.
The Spectre vulnerabilities are a bigger problem for AMD than the company previously believed.More news: Intel CEO addresses chip concerns at CES
AMD said in a statement after this story was initially published that there's been no change to its position on the susceptibility to the second variant of Spectre for its chips and only that it's rolling out optional updates to further contain the threat.
Now, however, Google is saying that not only did it know about the three specific Spectre and Meltdown CPU exploits, it worked to patch its own product line against a variant of Spectre that "was going to be much harder to mitigate". However, Intel still recommends end-users should apply the updates for both OS and hardware. Intel has also disclosed that the update includes performance hit on existing systems.
Both Microsoft and AMD have confirmed that they will be making the Meltdown and Spectre security updates available for Windows devices with AMD chips once again starting next week. While Microsoft has distributed Windows patches for the majority of AMD systems, the company acknowledged issues with those patches. "We are also working directly with data center customers to discuss the issue". "We expect this issue to be corrected shortly and Microsoft should resume updates for these older processors by next week". AMD's processors aren't "susceptible" to Meltdown, the chipmaker wrote, "due to [the company's] use of privilege level protections within paging architecture".