MIT researchers found a two-instruction timing gap that let interrupts defeat AMD's Safe RET mitigation on Zen 1 through Zen 4. The kernel fix was already merged before disclosure; separately, Linux 7.2-rc6 untangles a Zen 5/Zen 6 ID mixup.
One retail B850 board now boots on coreboot and openSIL, with a very short CPU list, while Zen 6's per-core performance floors are already merged in mainline Linux.
Discontinued X3D gaming CPUs have been selling far above their launch prices, with AM4 parts hit hardest. AMD's answer is unusual: reissue a four-year-old CPU and downclock a current one, both under $350. Here is what shipped, what it costs, and who each chip is actually for.
