AGESA 1.0.0.3: prevents boosting to over 5.5 GHz when more than 4 cores are active

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AMD released the AGESA 1.0.0.3 microcode for the AM5 platform and made relevant adjustments for the Ryzen 7000 series processors based on the Zen 4 architecture. This is also the first update after the release of the new platform.
In this AGESA 1.0.0.3 version, AMD re-added the “Precision Boost C-State Limiter” that was missing in the AGESA 1.0.0.2 version. This limiter limits the processor’s acceleration frequency to 5.5GHz or below when more than 4 cores are active in application scenarios such as rendering, large-scale games, and copy machine testing.

Image: SkatterBencher

Extreme overclocker SkatterBencher demonstrated this using NopBench on an ASUS ROG CROSSHAIR X670E EXTREME motherboard and a Ryzen 9 7950X processor. In the original 0046 or 0611 version BIOS, the 16 cores of the Ryzen 9 7950X processor can reach a clock of about 5.7GHz. After upgrading to BIOS version 0705 based on AM5 AGESA 1.0.0.3 microcode, the maximum clock can only be between 5.4GHz and 5.5GHz.

SkatterBencher finally concluded six points, namely:
  • First, enabling C-states is preferred as it provides higher performance for both AGESA 1002 and 1003.
  • Second, AGESA 1003 re-introduces the Precision Boost C-State Boost Limiter, which was not present on the launch motherboards & BIOSes
  • Third, the C-State Boost Limiter prevents the CPU from boosting to over 5.5 GHz when more than four cores are active. As the Ryzen 9 7950X has a programmed maximum frequency ceiling of 5.85 GHz, it means potential performance loss.
  • Fourth, on motherboards with the option, simply enabling “Medium Load Boostit” works around the C-State Boost Limiter.
  • Fifth, on motherboards that do not have this option, asynchronous eclk provides the only viable overclocking strategy to increase the frequency beyond 5.5 GHz when more than four cores are active.
  • Sixth, the real-world performance impact of the C-state Boost Limiter is minimal. That is because you need a good CPU capable of boosting over 5.5 GHz with many active cores. Furthermore, most workloads will trigger other Precision Boost limiters that restrict the operating frequency.

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