Intel is cutting off AVX-512 support from its Alder Lake lineup

Intel is purportedly cutting out AVX-512 support on Alder Lake CPUs for good, according to Igorslab. To do this, Intel will most likely issue a new microcode update to all…

By Nivedita Bangari

January 3, 2022

3 min read

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Intel is purportedly cutting out AVX-512 support on Alder Lake CPUs for good, according to Igorslab. To do this, Intel will most likely issue a new microcode update to all Alder Lake-supported motherboards that will prohibit any AVX-512 enablement workarounds from working. Additionally, with Rocket Lake, the business worked hard to deliver AVX-512 to general consumers; unfortunately, this will not be the case with Alder Lake.

For Intel’s 12th Gen Alder Lake platform, AVX-512 has been a strange and perplexing affair. Intel stated in our assessment of the architecture that the AVX-512 FMA is completely fused off on Alder Lake’s Golden Cove Performance cores. The AVX-512 instruction set was assumed to be physically disabled, with no ability to re-enable it via BIOS or other means.

However, Alder Lake customers quickly discovered that disabling the E-cores in the motherboard’s BIOS also enabled AVX-512 on the P-cores. According to another research from IgorsLab, this skill appears to have arisen by chance. With changes to the microcode in the motherboard UEFI/BIOS, motherboard manufacturers might reactivate AVX-512. Almost every motherboard manufacturer has taken advantage of this, making it a popular choice. Intel, on the other hand, was adamant that Alder Laker doesn’t officially support AVX-512, and that activating it could result in mistakes.

What’s more unusual is that performance from the AVX-512 instruction set is incredibly effective and efficient in specific workloads. For example, a month ago, we told you about an open-source PlayStation 3 developer named RPCS3 who saw considerable emulation performance increases when he activated AVX-512 on a Core i9-12900K.

IgorLabs also put AVX-512 to the test on Alder Lake and found it to be very good. Surprisingly, power efficiency with AVX-512 was better than AVX2, according to the German journal. It’s a big improvement over Rocket Lake when AVX-512 was more of a power hog than anything else.

Keep in mind that AVX-512 isn’t appropriate for all workloads. As a result, it’s better not to assume that the E-cores are lacking and that disabling them for the benefit of AVX-512 is always worthwhile. There are still a lot of workloads where having both P-cores and E-cores working together is beneficial.

Intel didn’t fuse off the AVX-512 instruction set on Alder Lake’s hardware in the end, and the chipmaker is working hard to eliminate AVX-512 capabilities for good shortly. We can hypothesize as to why Intel is doing this, but the best course of action is to prepare yourself for the transition. Of course, you can use an existing motherboard BIOS, but most boards will eventually have the revised microcode that disables AVX-512 functionality.