Recap: Reports suggest that a Windows 11 security update released in early August may be the cause of HDD and SSD failures during large data transfers. However, the extent of the issue remains unclear. At least one manufacturer claims it was unable to reproduce the problem, even after rigorous testing.
SSD manufacturer Phison says it has been unable to confirm whether Windows 11 24H2's KB5063878 update is responsible for storage drives crashing during file transfers larger than 50GB. The company is the first storage vendor to publicly respond to recent reports of crashes linked to the update.
Shortly after Microsoft released KB5063878 on August 12, users in Japan reported that numerous SSDs and HDDs became undetectable during large data transfers. In most cases, rebooting the system restored the drives – until another transfer was attempted. However, some drives required a full partition rewrite or reformatting.
Early reports suggested that around two dozen models from Samsung, Western Digital, Seagate, Corsair, Crucial, and other manufacturers were affected. The error appears to trigger when approximately 60 percent of a drive's storage capacity is in use.
So far, Phison is the only manufacturer to confirm that it is investigating the issue alongside Microsoft. However, in a statement to Wccftech, the SSD vendor said it could not reproduce the error after 2,200 test cycles and more than 4,500 cumulative hours of benchmarking. Although the cause of the initial reports remains unclear, Phison advised users to install heatsinks on NVMe SSDs to minimize thermal throttling.
The company also pushed back against accusations that its SSD controllers are particularly vulnerable to bugs stemming from the update. In an earlier statement, Phison claimed that a document circulating online allegedly describing severe issues with its drives is a hoax. So far, this denial, the acknowledgment of the initial reports, and the recent testing update remain the only official communications from Phison regarding the issue.
Meanwhile, as more cases of SSD failures following the Windows 11 update emerge from Japan, @Necoru_cat, the Twitter user who first reported the problem, is continuing to investigate and has begun corresponding with Microsoft. They also denied forgetting to install heatsinks on the affected SSDs, suggesting the root cause is likely unrelated to thermal management.
Users running Windows 11 24H2 may want to delay installing update KB5063878 for now. Those who have already applied the patch should exercise caution when transferring large amounts of data until more details are available.
Windows 11 update blamed for SSD failures, but Phison can't reproduce issue
