Despite Microsoft's claim, kernel reveals why Windows 11 isn't really faster than 10

For the longest time, since the public announcement of Windows 11 in around the middle of 2021, Microsoft has maintained that its newest offering was meant to get the best out of hardware. And it wasn't just empty words it seemed as the company also explained in detail how it planned to do so.

When users found certain elements of the OS were still not quite as snappy or smooth, Microsoft promised improvements were in the pipeline for 2022. Microsoft has continued to make performance claims and has also not hesitated to detail all such improvements it has made.

Intel users, especially, were promised better performance on Windows 11 as the 12th Gen (Alder Lake) and newer Intel processors, based on the hybrid Performance Hybrid architecture (or Big-Bigger) design, had specific optimizations for the Thread Director hardware scheduler.

However, these claims never really materialized into actual results that show significant differences. In July of 2022, almost a year after the initial performance claims of Intel 12th Gen were made, third-party testing showed that it was a mixed bag with neither of the OS being outright better. When similar testing was conducted half a year later with a focus on gaming, the results were again nothing too exciting.

Neowin also conducted a set of tests using the latest Intel 14th Gen CPU to see if we could find a palpable performance difference between the two, and again, our results were also in line with what others found. We also did two different tests, one for in-place upgrade and one where we clean installed.

This was certainly very surprising as the presence of dedicated hardware (Thread Director in this case) generally leads to better performance unless the OS itself is missing specific optimization.

Windows archive website BetaWiki may have the answer to why that is. Technology enthusiast and Twitter (now X) user Albacore performed a kernel mode Write to Model Specific Register (wrmsr) instruction for "MSR_IA32_HW_FEEDBACK_THREAD_CONFIG," they found that the Thread Director-specific optimizations were already present in Windows 10, going all the back to build 21301.

The build was released in February of 2021 which was a few months before Windows 11 was publicly revealed. On their Twitter post, Albacore writes:

I looked into which Windows versions support Intel's Thread Director — the key to correct scheduling among Efficiency and Performance cores on 12th gen & newer CPUs. Windows 10 build 21301 & newer + all of Windows 11 support it. The changes were never backported to older builds.

 

I performed the check by looking for a '__writemsr' instruction with target register 'MSR_IA32_HW_FEEDBACK_THREAD_CONFIG' (0x17D4) in the kernel. Checked latest Windows 10 & Server 2022 and I can confirm no such instruction exists. Builds 21301+ have it, regardless of edition.

Hence, it is likely that you will see actual performance improvement on your Intel 12th or newer chip if you were to upgrade from a build even older than 21301 to either Windows 11 or one of the latest Windows 10 releases.

Source