Some Windows 11 Users Claim Microsoft's New OS Is Seriously Gimping SSD Speeds

Then again, perhaps some of those aforementioned under-the-hood refinements are responsible for the technical issues that Microsoft's new baby has been facing. There were multiple issues on launch with AMD CPUs, a problem where the "chkdsk" tool could damage SSDs, and many users have reported general performance issues, including an overall "laggy" or "sloppy" feeling to the new OS.

Most of the results that we've observed were measured using Samsung SSDs, particularly the 980 Pro, but the issue is not confined to them. User Mussels84 offers the benchmark above that shows the issue clearly affecting a WD Black NVMe SSD—although curiously, it only affects the first partition on each drive. Meanwhile, JasonM_2020 tested his Optane DC P4800X drive and saw less than half of his Windows 10 performance on random writes. One user even claimed that his Crucial SATA SSD slowed the machine "to a crawl," although he neglected to provide any further details.

That doesn't mean there's no problem, though. Indeed, Reddit user Koopa777 claims to have tested the issue on his Samsung 980 Pro SSDs and found that while the performance degradation is relatively small—around 15%—when using a single thread, it's still degraded compared to Windows 10. He notes that adding more threads to the benchmark seems to make the issue worse, which would explain some of the terrible results we've seen from folks using 16 or more CPU threads to test random access performance.

Microsoft doesn't appear to have officially acknowledged this issue. A new Reddit poster named "neochristi" replied to a thread about the problem back some three months ago claiming to be a developer on "the Microsoft file systems team" asking for more information, but that Reddit account has never made any other posts, so who knows if that was legitimate.