Early independent testing has confirmed what many suspected: Windows 11 version 25H2, now in preview, delivers no measurable performance gains over its predecessor 24H2. In a head-to-head benchmarking suite run by Phoronix, the geometric mean across 41 CPU-intensive tests showed a 0% difference between the two Windows builds. The same tests also revealed that Ubuntu Linux—both the 24.04 LTS and the newer 25.10—outperformed Windows 11 by roughly 15%.

The 25H2 Update: An Enablement Package, Not a Full Kernel Rebase

Microsoft is shipping 25H2 as an enablement package (eKB) on top of the existing 24H2 servicing branch. Practically, this means the code for most new features has already been deployed to 24H2 machines inside monthly cumulative updates, but the features remain dormant until the tiny enablement package flips the necessary switches. The result is an update that behaves like a fast cumulative patch—requiring only a single reboot—rather than the full binary-level replace that once defined Windows feature updates.

For enterprise administrators, the model reduces downtime and simplifies validation. For the operating system itself, it all but guarantees that the kernel, scheduler, driver stacks, and core runtime libraries remain unchanged from 24H2. The only visible alterations are the removal of two legacy components (PowerShell 2.0 and the WMIC command-line tool) and a modest set of feature toggles and Group Policy controls.

The Benchmarking Reality: 24H2 vs. 25H2 Show Zero Net Gain

Phoronix tested a preview build of 25H2 against 24H2 and two Ubuntu releases on an AMD Ryzen 9 9950X system with 32GB of DDR5 memory. The suite comprised 41 cross-platform workloads, including renderers and compute benchmarks like LuxCoreRender, Embree, Intel Open Image Denoise, OSPRay, IndigoBench, and ASTC Encoder. The geometric mean across all tests showed:

  • Windows 11 25H2 performed identically to 24H2—0% improvement on average.
  • Both Ubuntu versions led the field, with an advantage of approximately 15% over Windows 11.

Individual tests fluctuated within the noise: LuxCoreRender tilted 2% in 24H2’s favor, while ASTC Encoder 5.0 gave 25H2 a 1.9% lead. No single workload produced a decisive OS advantage, and the overall picture is one of absolute performance parity between the two Windows versions.

Why No Performance Leap? The Engineering Behind the Scenes

Performance gains large enough to move a geomean require substantial low-level changes—scheduler redesigns that alter thread dispatch or cache affinity, new I/O or networking primitives, or major compiler/runtime optimizations. 25H2’s enablement approach does none of that. Because it shares a servicing branch with 24H2, every binary module the benchmark exercises is already present on a fully patched 24H2 machine. The enablement package flips feature flags; it does not recompile the kernel or replace foundational subsystems.

Microsoft’s servicing model deliberately avoids large-scale code rewrites in a mid-cycle update. That design prioritizes stability and lower patch complexity but guarantees that year-over-year performance on identical hardware will remain flat—unless a feature activation serendipitously improves a specific, narrow path. Phoronix’s CPU-heavy test selection, designed to expose OS scheduling differences, showed no systemic uplift, confirming that no such hidden gain exists.

User Impact: Who Should Care and Who Shouldn’t

For the vast majority of Windows users—those browsing, streaming, editing documents, or playing games at GPU-bound resolutions—the upgrade from 24H2 to 25H2 will be imperceptible. Gaming frame rates, application startup times, and multitasking responsiveness will stay the same. Content creators running rendering or encoding workloads will see identical completion times.

Enterprise IT departments, however, face a different calculus. The ability to roll out a feature update with a single reboot and minimal validation overhead is a win for fleet management. But the removal of PowerShell 2.0 and WMIC demands action: any legacy scripts, scheduled tasks, or third-party installers that rely on these deprecated tools will break. Admins must inventory and remediate such dependencies before broad deployment, or risk application and automation failures.

Linux advocates, meanwhile, will seize on Phoronix’s data. The 15% advantage for Ubuntu in CPU-bound compute workloads is not new, but it reinforces the narrative that Windows lags in certain developer and HPC scenarios. Users who operate render farms, compile large codebases, or run native Linux binaries may see tangible benefits from using Linux, though the gap depends heavily on the specific binary and toolchain.

The Strategic Shift: Microsoft’s Quiet Approach to Stability

25H2 exemplifies Microsoft’s evolving update strategy: safer, faster, and less disruptive. By staging feature code inside routine cumulative updates and activating it later, the risk of a major update introducing widespread regressions falls dramatically. This operational gain, however, comes at a perceptual cost. When a new version number arrives without any apparent improvement, users and the press are quick to view it as a maintenance update masquerading as a milestone.

The removal of PowerShell 2.0 and WMIC is technically laudable—reducing attack surface and legacy debt—but it introduces real migration pain for organizations that never modernized their automation. Such changes, while necessary, can sour the narrative around an otherwise stable release.

Practical Steps for Enterprises and Power Users

  • If you run 24H2 and value stability, there is no performance incentive to rush to 25H2. The code for its features already resides on your machine; the enablement package merely turns them on. You can apply it when convenient, knowing it will behave like a small cumulative update.
  • IT administrators should immediately begin auditing all automation for PowerShell 2.0 and WMIC dependencies. Replace ancient cmdlets with modern equivalents (PowerShell 5.1 or 7+, CIM/WMI cmdlets). Pilot the enablement package on a representative subset of devices to catch unexpected agent or driver incompatibilities.
  • Benchmarkers and enthusiasts comparing Windows vs. Linux for CPU workloads should mirror Phoronix’s methodology: use native binaries, control for toolchain differences, and run a large, diverse suite. Single-test wins can be misleading; only a geomean reveals the broader picture.

No Surprises, But a Clear Signal

Windows 11 25H2 was never expected to be a performance powerhouse. The enablement package format, the shared servicing branch, and the preview notes all pointed to a modest update. Independent benchmarks now confirm that the emperor has no new clothes: 25H2 brings zero measurable improvement to the CPU-intensive workflows tested by Phoronix, while Linux continues to hold a performance edge. For most Windows users, this is a non-event. For organizations managing compliance and compatibility, it’s a low-friction step forward—provided they clean house on legacy scripting first. The real story is not about what 25H2 adds, but about the era of quiet, unglamorous maintenance that Windows 11 has entered.