Software-defined Microarchitecture: An Arguably Terrible Idea, But Certainly Not The Worst Idea

Print Friendly, PDF & Email

James Mickens from Harvard University

In this video from HiPEAC 2020, James Mickens from Harvard University presents: Software-defined Microarchitecture: An Arguably Terrible Idea, But Certainly Not The Worst Idea.

All reasonable people are against tyranny. So why do we tolerate CPU vendors that keep their microarchitectural details partially hidden and weakly programmable? The networking people have already cast off their chains and allowed software-defined networking to free them from the cruelty of proprietary grey-box routers. Meanwhile, as the Layer 3 people exchange high-fives and champagne with the Layer 4 people, the developers of systems software for general-purpose CPUs are unable to configure important microarchitectural features that govern security, performance, and power consumption. In this presentation, I will describe some of the benefits that would emerge from a new kind of processor that aggressively exposes microarchitectural state and allows it to be programmed. Using elaborate hand gestures and cheap pleas for sympathy, I will explain why my proposals are different than prior “open microarchitecture” ideas like transport-triggered designs. Once my presentation is finished, I will distribute pitchforks and torches to audience members, who I will then exhort to burn down local fab plants as I maintain plausible deniability by locking myself in my hotel room and eating the tiny chocolates that only innocent people eat.

James Mickens is an associate professor at Harvard University. Excellence. Quality. Science. These are just a few of the words that have been applied to the illustrious research career of James Mickens. In the span of a few years, James Mickens has made deep, fundamental, and amazing contributions to various areas of computer science and life. Widely acknowledged as one of the greatest scholars of his generation, James Mickens ran out of storage space for his awards in 1992, and he subsequently purchased a large cave to act as a warehouse/fortress from which he can defend himself during the inevitable robot war that was prophesied by the documentary movie “The Matrix.” In his spare time, James Mickens enjoys life, liberty, and the pursuit of happiness, often (but not always) in that order, and usually (almost always) while listening to Black Sabbath.

Check out our insideHPC Events Calendar


  1. An arguably terrible idea? How so? It’s one of the best ideas to come along in years, at least if done right. Is there some sense that it will increase the burden on the application programmer? Not so. No change in the high-level languages. Huge increase in performance are possible. Best of all, it frees us from the tyranny of fixed data types (like IEEE 754 floats) that do not match the needs of workloads like AI.