Intel has had it with the AVX-512 instruction set. New Alder Lake CPUs are inadvertently compatible, and while that offers advantages for specific workloads, Intel is going to snub that compatibility anyway.
AVX-512 is a set of instruction extensions for the x86 architecture. Certain workloads take advantage of the presence of AVX-512 on a chip to run faster and more efficiently. However, Intel wants to keep AVX-512 as a purely commercial feature for professional chips, so the support should disappear from the Core range.
Not (officially) compatible
The new Intel Alder Lake twelfth-generation processors are therefore officially incompatible. The already introduced chips from that lineup combine two types of computing cores: Core-based P(restation) cores and Atom-based E(fficiency) cores. The E cores are not compatible with AVX-512 anyway, which seemed to solve the problem.
Soon that solution proved not foolproof. By disabling the E cores and using only the P cores, the processors became AVX-512 compatible again. Motherboard manufacturers implemented tweaks in their bios code to facilitate compatibility, despite Intel’s lack of official support.
Closed
That is now coming to an end, according to Igors Lab. That Web site knows from its own sources that Intel is requiring motherboard manufacturers to disable support in future updates.
The move is notable since Alder Lake handles AVX-512 quite well. The efficient implementation offers added value in certain cases, even when E-cores cannot cooperate. Intel’s motivation is most likely commercial. The processor maker wants to keep AVX-512 for more expensive workstation and server chips.
Intel is soon to launch new Alder Lake hardware, presumably including some models without E-cores. These would be fully AVX-512-compatible without the downside of the disabled E-cores, undermining any future Xeon offerings if AVX-512 remains enabled.