Intel confirms that Raptor Lake has been fixed with Microcode 0x12B

Intel’s Raptor Lake stability saga is over – New microcode fully addresses the issue’s root cause

Last month, Intel announced it had uncovered the “root cause” of the instability problems plaguing its Raptor Lake series CPUs. Now, Intel has confirmed that its 0x12B microcode update is the final fix for 13th/14th generation Raptor Lake CPU instability. Simply put, this fix addresses the issue in its entirety.

Intel Raptor Lake CPU users should update their motherboard’s BIOS to add Intel’s fix to their systems. This should prevent these CPUs from becoming unstable.

Yes, we’re confirming this is the cause and that it is fixed.

– Intel’s Thomas Hannaford to The Verge

This year, Intel released four mitigations for its Raptor Lake CPU instability issues. The last of these Raptor Lake fixes is the 0x12B microcode. Additionally, Intel has confirmed that this issue is not present in their new Lunar Lake and Arrow Lake processors.

Below is what Intel had to say about their “Vmin Shift Instability” issue and their mitigations.

Intel has localized the Vmin Shift Instability issue to a clock tree circuit within the IA core which is particularly vulnerable to reliability aging under elevated voltage and temperature. Intel has observed these conditions can lead to a duty cycle shift of the clocks and observed system instability.

Intel has identified four (4) operating scenarios that can lead to Vmin shift in affected processors:

1. Motherboard power delivery settings exceeding Intel power guidance.
   a. Mitigation: Intel Default Settings recommendations for Intel Core 13th and 14th Gen desktop processors.
2. eTVB Microcode algorithm which was allowing Intel Core 13th and 14th Gen i9 desktop processors to operate at higher performance states even at high temperatures.
   a. Mitigation: microcode 0x125 (June 2024) addresses eTVB algorithm issue.
3. Microcode SVID algorithm requesting high voltages at a frequency and duration which can cause Vmin shift.
   a. Mitigation: microcode 0x129 (August 2024) addresses high voltages requested by the processor.
4. Microcode and BIOS code requesting elevated core voltages which can cause Vmin shift especially during periods of idle and/or light activity.
   a. Mitigation: Intel is releasing microcode 0x12B, which encompasses 0x125 and 0x129 microcode updates, and addresses elevated voltage requests by the processor during idle and/or light activity periods.

So, what was Intel’s “Vmin Shift Instability” root cause? The simple answer was that Intel’s chips were asking for too much voltage, which was damaging parts of their CPUs. Intel has addressed this issue with new microcode, allowing its chips to request corrected voltages, leading to long-term CPU stability.

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