I have only skimmed these articles, but they address your question regarding POWER: https://wiki.raptorcs.com/wiki/Speculative_Execution_Vulnerabilities_of_201

I have only skimmed these articles, but they address your question regarding POWER: https://wiki.raptorcs.com/wiki/Speculative_Execution_Vulnerabilities_of_2018 https://wiki.raptorcs.com/wiki/Speculative_Execution_Vulnera... https://www.ibm.com/blogs/psirt/potential-impact-processors-power-family/ https://www.ibm.com/blogs/psirt/potential-impact-processors-... https://www.talospace.com/2018/08/l1-terminal-fault-another-good-day-to.html https://www.talospace.com/2018/08/l1-terminal-fault-another-... http://tenfourfox.blogspot.com/2018/07/netspectre-not-much-of-powerpc-threat.html http://tenfourfox.blogspot.com/2018/07/netspectre-not-much-o... http://tenfourfox.blogspot.com/2018/01/actual-field-testing-of-spectre-on.html http://tenfourfox.blogspot.com/2018/01/actual-field-testing-... http://tenfourfox.blogspot.com/2018/01/more-about-spectre-and-powerpc-or-why.html http://tenfourfox.blogspot.com/2018/01/more-about-spectre-an... http://tenfourfox.blogspot.com/2018/01/is-powerpc-susceptible-to-spectre-yep.html http://tenfourfox.blogspot.com/2018/01/is-powerpc-susceptibl... The _Talospace_ and _TenFourFox Development_ articles are by Cameron Kaiser, who is active on HN (and Blogger) as classichasclass. Edit: Add missing 'and' in last sentence.