Thread Director
Intel's hardware mechanism that helps the operating system's scheduler place the right thread on the right core type (P or E) in a heterogeneous chip. It gives the OS real-time "hints" about each thread's character, so the scheduling is better than the OS could guess on its own.
Problem: in a heterogeneous chip someone must decide which thread belongs on a large P-core and which can make do on a small E-core — and a wrong decision wastes either energy (a heavy thread in the wrong place) or performance (a light thread blocking a P-core). The OS alone has poor insight into what a thread actually does at the micro level. Thread Director sits in the hardware, monitors each thread's behavior (instruction mix, how much it benefits from a wide core) in real time, and provides the OS with ranked guidance ("this thread gains a lot from a P-core, this one doesn't"). The scheduler (Windows/Linux) uses the hints to place and move threads. Crucial for heterogeneous chips to perform well — early Alder Lake problems were partly due to immature scheduling. Related to heterogeneous cores and P-core/E-core.