[The Exiled]

Intel unveils Alder Lake Development Guide for hybrid architecture optimization

Alder Lake will come with Golden Cove-based Performance cores (or P-cores), and Efficiency cores (E-cores) that are based on the Gracemont Atom-class architecture. Having two different types of CPU cores in the same system isn't a completely new concept, particularly in the Arm world, but it's nearly unprecedented in the Windows-on-x86 universe (Intel has dabbled with Lakefield). To help developers deal with the change-over, Intel has now published a developer guide for Alder Lake. It's pretty in-depth, and applicable to any type of software, although it is primarily targeted at game developers. There are a lot of tips for game programmers looking to make sure their software runs well on Intel's forthcoming hybrid chips, as well as example software on GitHub.

Overall the guide is very encouraging as a Windows PC gamer. Intel specifically states that "games are a critical segment for Alder Lake-S, and no performance loss is acceptable." It goes on to acknowledge that while games are usually GPU-bound, fast discrete GPUs can shift the bottleneck over onto the CPU in a single-threaded fashion. Intel says "it is difficult to remove work from the critical game threads [...] Amdahl’s Law often prevents core-count scaling beyond six to eight cores, but this does not mean that games do not use more than six to eight threads/cores."

The company advises a major change in the way games schedule threads; rather than doing it by hand, Intel says developers should use Windows APIs to signal the system scheduler, indicating which threads are time-sensitive and which threads are "background" tasks. The guide also details numerous scenarios in which developers could shunt tasks like AI, physics, pathfinding, and sound processing off to the E-cores, allowing the P-cores to focus on intensive threads like a game's main render thread. One final important thing to note is that the guide implies that game performance could collapse on Windows 10 compared to Windows 11. As noted above, Intel recommends that developers let the system scheduler (with some API prodding) handle thread scheduling, but doing so requires heavy reliance on the Intel Thread Director, which is a hardware-assisted scheduler that Intel has talked about before.

Izvor: HotHardware