The End of SCSI: Windows Server 2025 Unlocks 70% Faster Storage with Native NVMe I/O

Windows Server 2025 on systems with NVMe SSDs gains a substantial uplift thanks to native NVMe I/O, a feature introduced with the October 2025 cumulative update but not enabled by default. Administrators must activate it via registry changes or group policy, after which Microsoft projects up to 70% more IOPS under heavy I/O loads and CPU utilisation reductions of as much as 45%, according to Ignite conference data presented by Microsoft.

Previously, NVMe SSDs used a SCSI/SATA compatibility stack, but the new I/O path provides a direct, streamlined channel that exploits multi-core parallelism and allows each core to handle I/O queues more efficiently.

In testing on a dual-socket Intel server with 208 logical cores, 128 GB of memory, and a Solidigm D7-PS1010 3.5 TB PCIe 5.0 SSD, IOPS rose by 45% with a single I/O thread, 78% with eight threads, and 71% with sixteen threads, while 4K random read CPU utilisation fell by 41% (eight threads) and 47% (sixteen threads).

The technology appears best suited to AI workloads and data-intensive tasks such as large-scale database storage, though consumer Windows variants may require further validation and are unlikely to receive native NVMe I/O in the near term.