Intel Microcode 0x12B explained CPU Test with Extreme Tuning Utility

A Rollercoaster Ride with Intel’s Replacement CPU has good Performance Gains

After hearing about instability issues with the Intel Core i7-1400K and my processor not hitting full speed, the Intel(R) Extreme Tuning Utility showed even slower performance and thermal throttling. Intel support organized an RMA.

I received a replacement CPU from Intel, and to ensure optimal stability, I applied the latest BIOS 7E06vH7 patch from MSI for my Z790 Gaming motherboard. The updates included:

• – Update CPU Microcode 0x12B
• – ME Firmware ver: ME_16.1.32.2473

These updates were intended to fine-tune the processor’s performance and address any lingering instability issues.

After this, I then installed Windows 11.

The most notable enhancement was its ability to reach the full 5.6GHz speed, from the 5.3GHz I had previously managed. Additionally, the operating temperatures saw a remarkable drop—from 38°C to a cooler 32°C.

Intel® has identified four operating scenarios that can lead to Vmin shift:

Motherboard Power Delivery Settings: Settings exceeding Intel’s power guidance.
Mitigation: Follow Intel® Default Settings recommendations for Intel® Core™ 13th and 14th Gen desktop processors.

eTVB Microcode Algorithm: This algorithm allowed Intel® Core™ 13th and 14th Gen i9 desktop processors to operate at higher performance states even at elevated temperatures.
Mitigation: Microcode 0x125 (June 2024) addresses the eTVB algorithm issue.

Microcode SVID Algorithm: This algorithm requests high voltages at certain frequencies and durations, potentially causing Vmin shift.
Mitigation: Microcode 0x129 (August 2024) addresses the high voltages requested by the processor.

Microcode and BIOS Code: These can request elevated core voltages, particularly during idle or light activity periods, which may lead to Vmin shift.

Mitigation: Intel® will release microcode 0x12B, which incorporates both 0x125 and 0x129 updates to address elevated voltage requests during idle and light activity.

Below are HWinfo screenshots of both my CPU’s for comparison. It seems my original processor did have max Turbo speed.

Just to add I have AI system management software which may reduce idle speed.

Despite these promising improvements, the journey took an unexpected turn. After the initial bluescreen crash, it is now ok and has passed tests.

After the update, you need to remove the Intel® Processor Diagnostic Tool and reinstall it.

Change the ‘CPU Lite Load” in the BIOS from auto to Intel.