a massive performance loss. Despite this, AMD has managed to design Zen 4 such a way its performance is not affected by mitigations. Vulnerabilities and mitigations summary Hardware mitigations require change to the CPU design and thus a new iteration of hardware, but impose close to zero performance loss. Microcode updates alter the software that the CPU runs on, requiring patches to be released and integrated into every operating system and for each CPU. OS/VMM mitigations are applied at the operating system or virtual machine level and (depending on workload) often incur quite a significant performance loss. Software recompilation requires recompiling every piece of software and usually incur a severe performance hit. The 8th generation Coffee Lake architecture in this table also applies to a wide range of previously released Intel CPUs, not limited to the architectures based on Intel Core, Pentium 4 and Intel Atom starting with Silvermont. Various CPU microarchitectures not included above are also affected, among them are IBM Power, ARM, MIPS and others. Intel CPUs past Ice Lake, e.g. Rocket Lake and Tiger Lake are not affected by Fallout/MSBDS. Notes 1.Stepping 5 of the 2nd Generation Intel® Xeon® Scalable Processors based on Cascade Lake microarchitecture is affected by both MSBDS and MLPDS. References External links Vulnerabilities associated with CPU speculative execution A systematic evaluation of transient execution attacks and defenses A dynamic tree of transient execution vulnerabilities for Intel, AMD and ARM CPUs Transient Execution Attacks by Daniel Gruss, June 20, 2019 CPU Bugs Intel: Refined Speculative Execution Terminology Hardware bugs Side-channel attacks