While testing Intel Alder Lake Desktop CPUs, we found that AVX-512 support has not changed and can be easily enabled, although this instruction set is completely disabled by an upcoming BIOS.
Intel Alder Lake desktop CPUs lose their AVX-512 instructions with the next major BIOS from motherboard manufacturers
Although Intel’s Alder Lake CPUs are not officially mentioned as compliant with the AVX-512 instructions, they can be activated by disabling the active “Gracemont” cores and leaving the “Golden Cove” performance cores turned on. This provides slightly better performance and greater efficiency than standard AVX2 instructions. While electronic cores have their own advantages on various workloads, the AVX-512 instructions also seem to achieve greater efficiency.
But that is about to change. Igor’s laboratory Reports indicate that Intel has been directing motherboard manufacturers to remove AVX-512 support on Alder Lake CPUs with an upcoming BIOS update. Not surprisingly, this change came just days before Intel plans to launch it. A different variety from Lake K Alder Which will feature most P-core only models (Core i5 and Core i3 for non-hybrids).
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Performance Intel AVX-512 vs. AVX2 on Alder Lake CPUs. (Image credits: Igor Lab)
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These chips have the potential to be an important item for entry-level servers and workstations where their AVX-512 features can be used. Intel doesn’t want this to happen, and as such they are doing their best to remove instruction set support from the equation. There’s more, however, and Igors Lab explains that the AVX2 standard guidelines have a very strict thermal acceleration advantage on all hybrid chips that are recognized in HWiNFO as “IA: Turbo High Limit – Yes”.
Support / Limits for Intel Alder Lake AVX512 and AVX2 on HWiNFO (Image Credits: Igor Lab):
Thermal lockup results in limited clock speeds and the stated reason is to avoid deterioration of electron transfer within new chips. There are now few systems that can reach the maximum clocks of 5.2 GHz for the chip because of this accelerator because many computers will not have enough cooling to reach these high clocks.
Fortunately, there are already solutions for these two AVX hurdles, AVX2 acceleration and AVX-512 release. For example, Asus has implemented a patch in their BIOS versions for “Maximus” series motherboards that disable the AVX2 controller. The only important thing here is that the clock must already be set in the BIOS at boot time. Otherwise, a subsequent software change within the operating system will be on Intel’s fishing net again.
Fortunately, there are already solutions for these two AVX hurdles, AVX2 acceleration and AVX-512 release. For example, Asus has implemented a patch in their BIOS versions for “Maximus” series motherboards that disable the AVX2 controller. The only important thing here is that the clock must already be set in the BIOS at boot time. Otherwise, a subsequent software change within the operating system will be on Intel’s fishing net again.
Now you can keep the existing BIOS and keep the AVX-512 instructions, but it is expected that newer stock motherboards will have no BIOS. Also, you’ll definitely need a better BIOS than what’s available at launch to get good stability and DDR5 compatibility for your Alder Lake CPUs, but upgrading means saying goodbye to the instruction set. So it’s a really weird move by Intel, and if they were so pissed off about this advantage over consumer CPUs, they shouldn’t have it in the first place.
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