How to Change Intel CPU Microcode

If you need to change the microcode but still want the latest BIOS features and fixes, you’re in luck! I’ll share how I managed to do this relatively easily.

Why do You Want to Change the Microcode?

Depending on the generation of Intel CPUs, you might have different reasons for this:

• You may want to receive security enhancements, stability improvements, and performance optimizations from the latest microcode released by Intel, but your motherboard manufacturer has abandoned support or failed to keep the microcode up to date.
• In my case, downgrading the microcode helps regain 5-30% of the performance lost (depending on the workload) due to Spectre and Meltdown patches.

Things you’ll need

• Python - Download
• UEFI BIOS Updater (UBU) - UBU_v1_80_a17_fixed.zip
• HWinfo64 - Download
• Old & new BIOS file of your motherboard

Preparations

1. Install Python.
2. Extract the old & new BIOS files in seperate folder.
3. Extract UBU_v1_80_a17_fixed.zip.
4. Open Hwinfo64 and take note CPU ID from there.

How to do it (Step-by-Step)

Flashing modified BIOS may brick your motherboard.

Part 1: Extracting Old Microcode from the Old BIOS File

1. Delete bios.bin from the UBU folder if present.
2. Open UBU.cmd and select your old BIOS file (e.g., E7B53IMS.110).
3. Choose Do not use MMTool (press 0).
4. Select CPU Microcode (press 5).
5. Press X to extract all CPU microcodes, then close the window.
6. Go to .\Extracted\Intel, find the file matching your CPU ID (e.g., cpu906EA_...), and copy it.
7. Paste it into .\Files\intel\mCode\USR_mCode.
8. Run GenUSRmC.bat in .\Files\intel\mCode, then close it.
9. Part 1 complete.

Part 2: Replacing the Microcode in the New BIOS File

1. Delete bios.bin from the UBU folder if present.
2. Open UBU.cmd and select your new BIOS file (e.g., E7B53IMS.1D0).
3. Choose Do not use MMTool (press 0).
4. Select CPU Microcode (press 5).
5. Press U to replace microcode using USR_mCode.txt.
6. Confirm the “Checksum correct” message.
7. Press R to start the replacement, then press any key.
8. Exit the tool, rename the new file if necessary (e.g., mod_E7B53IMS.1D0), and flash it.
9. Part 2 complete.

You can proceed to flash the BIOS that you have modified.

Flashing modified BIOS may brick your motherboard.

Before	After

Research

• Update Your CPU BIOS Microcode - More Performance - Less Consumption - BIOS Modding - Overclocking
• Latest Overclocking Programs, System Info, Benchmarking, & Stability Tools
• [Tool Guide+News] “UEFI BIOS Updater” (UBU)