Windows 11: According to users on Reddit and the Microsoft forums, Windows 11 is making some NVMe SSDs much slower, with write speeds up to 48% slower. Some of the reports are from when the new system was still in preview.
Although Windows 11 has already been officially released to the general public, it continues to have some performance issues. Tests using CrystalDiskMark and AS-SSD indicate that the most affected parameter is non-sequential writing operations.
In a first test, the Samsung 980 SSD showed non-sequential write speeds of 1601.03 MB/s in Windows 10 and only 911.29 MB/s in Windows 11. The performance issue was already being reported by users participating in the Windows Insider test program and apparently continue to affect both PCI Express 4.0 models and older drives.
VBS contributes to problem, but there’s more
One of the factors that apparently affects performance is virtualization-based security (VBS), which also affects performance in games. However, even disabling VBS the speed gain still does not reach the performance of the same drives in Windows 10, suggesting that the security system is not the main responsible.
A recent post suggests that the new build 22000.348, released on November 22nd, has improved the result a bit, but still hasn’t fixed the issue.