Intel Alder Lake desktop CPUs loose their AVX-512 instructions with the next major BIOS from motherboard manufacturers
While testing Intel Alder Lake desktop CPUs, we found that AVX-512 support remained unaffected and could easily be enabled, even though this instruction set would be completely disabled by an upcoming BIOS.
Intel Alder Lake desktop CPUs loose their AVX-512 instructions with the next major BIOS from motherboard manufacturers
Although Intel's Alder Lake CPUs are not officially mentioned as supporting AVX-512 instructions, they can be enabled by disabling active “Gracemont” cores and leaving “Golden Cove” power cores on. This provides slightly better performance and greater efficiency than the standard AVX2 instructions. While electronic cores have their own advantages in a number of workloads, AVX-512 instructions also appear to be more efficient.
But that's set to change , according to reports, Intel has instructed motherboard manufacturers to remove AVX-512 support on Alder Lake CPUs with an upcoming BIOS update. Unsurprisingly, this move was made a few days before Intel launched a variety other than K Alder Lake that will contain the majority of the pure P-Core models (Core i5 and Core i3 aren't hybrids).
Performance of Intel AVX-512 vs. AVX2 on Alder Lake CPUs. (Photo credit: Igor Lab)
These chips have the potential to become a hot item for entry-level servers and workstations where their AVX-512 features can be used. Intel doesn't want this to happen so are doing their best to remove instruction set support from the equation. There is more, however, and Igors Lab explains that the AVX2 standard guidelines have a very strict thermal throttling benefit for all hybrid chips recognized in HWiNFO as "IA: Max Turbo Limit - Yes".
Support / Limits for Intel Alder Lake AVX512 & AVX2 at HWiNFO (Photo credit: Igor's Lab):
Thermal locking results in limited clock rates and the reason given is to avoid degradation of electron transfer within the new chips. There are now only a few systems that can achieve the maximum 5.2 GHz clocks for the chip due to this throttling, as many computers do not have enough cooling to achieve these high clocks.
Fortunately, solutions already exist for both of these AVX hurdles, AVX2 throttling and AVX-512 clearance. For example, Asus has implemented a patch in its BIOS versions for mainboards of the “Maximus” series that deactivates the AVX2 control. The only important thing here is that the clock must already be set in the BIOS when booting. Subsequent changes via software within the operating system are otherwise back in Intel's fishing net.
Fortunately, solutions already exist for both of these AVX hurdles, AVX2 throttling and AVX-512 clearance. For example, Asus has implemented a patch in its BIOS versions for mainboards of the “Maximus” series that deactivates the AVX2 control. The only important thing here is that the clock must already be set in the BIOS when booting. Subsequent changes via software within the operating system are otherwise back in Intel's fishing net.
You can now stick with your existing BIOS and keep the AVX-512 instructions, but the latest standard motherboards are unlikely to have a BIOS anymore. Also, to get good stability and DDR5 compatibility for your Alder Lake CPUs, you definitely need a better BIOS than the one available at startup, but upgrading means saying goodbye to the instruction set. So it's a really strange move by Intel, and if they were so annoyed about this one advantage over consumer CPUs, they shouldn't have had it in the first place.
