Intel 14th & 13th Gen CPU Performance Tested With Latest Intel 0x12B Microcode Patch BIOS

The Intel 0x12B patch is the third update for Vmin Shift Instability mitigation, which was released a few days ago but there seems to be performance loss with this one when running a 14th or 13th Gen Core i9 CPU.

Intel's 0x12B Microcode BIOS Patch Does Seem To Affect 14th & 13th Gen Core i9 CPU Performance A Bit

Intel recently delivered a new 0x12B microcode BIOS patch for Intel 14th & 13th Gen Core i9 CPUs. This is the third in the series, which succeeds the 0x129 released in August. We have covered the updates for the 0x12B update in one of our posts, which also shed some light on the performance Intel wants users to expect with it.

Related Story Intel Rolls Out Third Major “0x12B” Microcode Patch To Fix 14th & 13th Gen CPU Instability Issues

As per Intel's original blog post, the company stated the performance impact will be within the "run-to-run" variation, including some synthetic apps such as Cinebench R23, Speedometer, Crossmark, etc. Run-to-run variation is where you find the performance difference almost unnoticeable and is generally under the margin of error. This means that a +-1% performance difference is expected when you run the same application a few times with the same hardware parameters.

However, this doesn't seem to be the case with the new BIOS patch. As tested by the Chiphell forum user 'twfox', Intel CPUs are seeing a performance loss in synthetic benchmarks. The user tested the Intel Core i9 13900K processor on an ASUS motherboard and showed some interesting stuff. One of them is the removal of the option that lets users disable C1E in BIOS, which keeps the processor stress at bay while maintaining CPU stability.

This has also been confirmed from the BIOS release notes by various motherboard vendors, which have released the 0x12B BIOS update for their LGA 1700. But as far as the performance goes, the Intel Core i9 13900K saw a noticeable 6.5% drop in performance in Cinbench R15. As seen in the screenshot, the Intel Core i9 13900K usually