Intel BIOS Updates Officially Disable Alder Lake's AVX-512 Capabilities

News
By
published

Goodbye AVX-512, you'll be missed!

12th Generation Alder Lake Processor
(Image credit: Intel)

A few days ago, we discovered Intel's plans to kill off AVX-512 enablement on Alder Lake CPUs permanently. Now, as reported by hardwareLuxx, BIOS updates for Z690 motherboards with new Intel microcode have been released that officially disable AVX-512 for good.

HardwareLuxx demonstrated the changes by using both an ROG Maximus Z690 Hero with BIOS version 0702 and an MSI Z690 Unify with BIOS version 1.13 paired to a Core i9-12900K. When enabling AVX-512 in the BIOS (which also means disabling the E-cores) and booting into Windows, "AVX512F" support can be seen clearly within CPU-Z. However, when BIOS version 1.21 was installed on the MSI Z690 Unify, hardwareLuxx notes that the AVX-512 instruction set is completely missing from CPU-Z, despite there still being an AVX-512 toggle within the BIOS.

More specifically, the BIOS comes with Intel microcode version 18, which is an update from the previous MSI BIOS that was equipped with version 15. So it seems any motherboard BIOS with a microcode update to 18 (or later) will completely disable AVX-512. That will happen whether or not there are AVX-512 toggles within the BIOS.

It's also worth noting that hardwareLuxx tested an MSI B660 motherboard and found all AVX-512 functionality was missing from the BIOS. By this, we presume Intel has already applied the new microcode to these newer motherboards. That means we can expect all 600-series chipset boards besides Z690 to automatically lock out AVX-512 support altogether.

If you want to keep AVX-512 enablement on your Alder Lake system, you'll need a Z690 motherboard and will need to stick with a BIOS that has not been updated to the latest Intel microcode.

Also worth noting is that this new microcode appears to enforce a multiplier limit of 51 (5.1GHz) when using the AVX2 instruction set. This limit is present in all Alder Lake boards, but the new microcode update now prevents you from overriding that limit. It's not clear if this was done in response to problems that were happening or if this is merely a proactive measure to prevent potential issues in the future.

See more Motherboards News
Aaron Klotz
Aaron Klotz
Contributing Writer

Aaron Klotz is a contributing writer for Tom’s Hardware, covering news related to computer hardware such as CPUs, and graphics cards.

7 Comments Comment from the forums
  • -Fran-
    Is there a performance penalty to disabling AVX512 via microcode?

    Regards.
    Reply
  • Tech0000
    I guess there will be an opportunity to mod all new bios with uCode 5 using UBU (about a few minutes worth of work per BIOS). Not a big deal. Pathetic attempt by Intel to kneecap their new CPUs to create artificial differentiation.
    Reply
  • Tech0000
    -Fran- said:
    Is there a performance penalty to disabling AVX512 via microcode?

    Regards.
    Yes, In certain workloads there is a penalty. Looks like Intel actually got AVX512 right in the golden cove. See other Tomshardware article for bechmark details... https://www.tomshardware.com/news/intel-reportedly-kills-avx-512-alder-lake-cpus
    Reply
  • PCWarrior
    -Fran- said:
    Is there a performance penalty to disabling AVX512 via microcode?
    There is no performance penalty from the new microcode per se. Of course, if you are one of the few people that bought an i9 12900K and then went to the BIOS and disabled all the E-cores and enabled AVX-512 (something possible on a few vendors' motherboards only) you will obviously lose the capability of utilising AVX-512. AVX-512 is currently only utilised by a handful of workloads, one of them being y-cruncher. Benchmarks on y cruncher show that 8 P-cores (with AVX 512 disabled) + 8 E-cores is around 12% slower than 8 P-cores (with AVX512 enabled) + 0 E-cores (remember you have to disable all the E-cores in order to be able to enable AVX-512). That also correlates well with the PS3 emulation results (68FPS Vs 78FPS) mentioned above.
    Reply
  • JamesJones44
    I really don't understand this move. I'm not a fanboy of either company, give me the best at the best price. However, this reeks of Intel taking away a feature to later upsell with a workstation class setup where it magically reappears. Maybe there is an issue with it, but thus far, people who have enabled it haven't reported any issues and Intel's silence on it makes it even more questionable as to the reason why.
    Reply
  • Krotow
    The real question is - are AVX-512 disabling outside virtual pissing contest benchmark utilities will cripple performance in more useful real aplications and games?
    Reply
  • TerryLaze
    JamesJones44 said:
    I really don't understand this move. I'm not a fanboy of either company, give me the best at the best price. However, this reeks of Intel taking away a feature to later upsell with a workstation class setup where it magically reappears. Maybe there is an issue with it, but thus far, people who have enabled it haven't reported any issues and Intel's silence on it makes it even more questionable as to the reason why.
    They cut off avx-512 and limited avx2 to 5.1Ghz so the trend is pretty clear, they have to enforce their power draw and cooling designs, most likely because people where abusing them, mobo makers are pushing too much power into the CPUs and reviewers use "out of the box" as an excuse to push the CPU.

    At some point intel has to cut their losses here, they always advertised alder as not having avx-512 so they are not taking anything away from people that they payed for.
    Reply