AMD and Intel Are Jointly Changing a 40-Year-Old Foundation of Processors

A revolution is brewing in the world of processors. According to the latest data, future AMD processors (Zen 6) will incorporate Intel's interrupt handling technology called FRED (Flexible Return and Event Delivery). This move signifies not just an update, but an abandonment of a fundamental mechanism that has been at the core of all x86 systems since 1982.

Currently, the system's response to mouse movement, a network packet, or a completed disk operation is handled by the Interrupt Descriptor Table (IDT). This system debuted with the Intel 80286, and the most astonishing thing is that for over 40 years, despite a colossal increase in performance, this low-level mechanism has remained virtually unchanged. The new interrupt handling technology is designed to replace it.

The new technology treats interrupts as a single, unified operation, simplifying the interaction between user code and the system kernel. This, in turn, reduces the risk of errors during simultaneous events and removes extra steps that consumed valuable CPU clock cycles. AMD's move is part of a larger process: both AMD and Intel are members of the x86 Ecosystem Advisory Group, formed in 2023 to unify the instruction set. The adoption of FRED in Zen 6, as well as in upcoming Intel Nova Lake and Panther Lake chips, is an example of coordination in a historically competitive environment.

Interestingly, AMD had its own alternative path—the Supervisor Entry Extensions (SEE) technology—but the industry, including Linux creator Linus Torvalds, leaned towards Intel's more holistic solution. Torvalds has publicly endorsed FRED as a way to address long-standing architectural shortcomings. End-users are unlikely to see new buttons in their interfaces. All the work will happen at the level of operating systems and drivers.

The most noticeable performance gains may manifest in virtualization, where reducing CPU overhead directly leads to increased efficiency. Thus, the move to FRED in Zen 6 is not just an "update," but a step towards modernizing the very foundation of the x86 architecture, which could bring improvements in latency-sensitive scenarios.