- Windows 11 updates KB5062660 and KB5063878 are not causing consumer SSDs to fail or become bricked.
- Failures reported online were traced to outdated firmware in the storage devices and the motherboard.
- Phison confirms that SSDs from official channels remain safe, and slowdowns under heavy writes are normal behavior that can be resolved with a Secure Erase.
- If you’ve been affected, you should update the SSD firmware and the motherboard’s UEFI (BIOS) immediately.
UPDATED 9/11/2025: Windows 11 updates KB5062660 and KB5063878 are not bricking consumer SSDs. Failures reported online were traced to outdated firmware in the storage devices and motherboard UEFI (BIOS), not the operating system itself.
Phison, the SSD controller manufacturer at the center of the controversy, confirmed that “early versions of firmware and BIOS” were to blame for the issues, not Microsoft’s updates. Drives sold through official retail channels with validated firmware remain safe.
Why SSD failures made headlines
Soon after Microsoft released the August 2025 Security Update preview (KB5062660) and final rollout (KB5063878), users began reporting that SSDs were failing or disappearing under heavy sustained write loads of 50GB or more, particularly when the drive was over 60 percent full. The problem quickly gained traction on social media and YouTube, where many blamed Microsoft’s patch history.
One high-profile case came from YouTuber JayzTwoCents, who demonstrated a Crucial T500 with a Phison E25 controller failing after the update. However, in a follow-up video, he admitted his system was running a beta BIOS and that updating the firmware resolved the issue.
Meanwhile, Taiwanese hardware outlet PCDIY (via Reddit) conducted joint testing with Phison engineers. Failures were reported on media review units of SSDs, such as the Corsair Force Series MP600 2TB (E16 controller) and Silicon Power US70 2TB, but not on retail drives. The affected samples were confirmed to be running engineering preview firmware, not the production firmware shipping to consumers.
What Phison and Microsoft found
Michael Wu, GM and President of Phison US, clarified in a statement to The Verge:
Many of the reports originate from media testing conducted on hardware running early versions of firmware and BIOS. We have observed that outdated firmware is still being used on some SSDs, and we encourage any reviewers facing this to leverage updated channel firmware readily available through manufacturer-provided update utilities.
Phison also noted that its own testing (more than 4,500 hours) showed no failures on retail drives. Microsoft has also stated that it had “found no connection” between the August updates and consumer SSD crashes.
What Windows 11 users should know
It’s been concluded that retail devices using the final intended firmware version are not affected by the critical bug found in engineering samples.
Additionally, Phison has confirmed that slowdowns are expected under heavy write conditions. Once the SLC cache and over-provisioned space fill up, SSDs write directly to TLC/QLC NAND, which is slower. This behavior is normal across modern SSDs.
If you want to resolve this performance issue, a simple hard drive format won’t restore speeds. You should perform a Secure Erase using the manufacturer’s software or motherboard UEFI tools (such as those on ASUS or ASRock boards) to refresh the drive and regain full performance.
In the case that you’re experiencing this issue, it’s recommended to update both the SSD firmware and the motherboard UEFI/BIOS to the latest official versions to avoid issues.
Final takeaway on the Windows 11 SSD issue
Despite initial concerns, Windows 11 updates are not causing retail SSDs to fail. The issue was isolated to review units running outdated firmware, and the consumer drives remain safe, and any performance degradation under extreme workloads can be reversed with a proper secure wipe.
Also, using an outdated version of the motherboard’s UEFI (BIOS) has been confirmed to contribute to the SSD problem.
If you have previously uninstalled the update KB5063878 (build 26100.4946), you should reapply the cumulative update after confirming that the storage drive and motherboard have the latest firmware version.
In addition, it remains critical to maintain a full backup of your computer on an external drive. You should also combine this backup with a file backup to the cloud or another storage, as you never know when another update or a piece of hardware may fail.
Update, September 11, 2025: This content has been updated with new information regarding the SDD and motherboard firmware as the root cause.
Mauro Huculak is a Windows How-To Expert and founder of Pureinfotech in 2010. With over 22 years as a technology writer and IT Specialist, Mauro specializes in Windows, software, and cross-platform systems such as Linux, Android, and macOS.
Certifications: Microsoft Certified Solutions Associate (MCSA), Cisco Certified Network Professional (CCNP), VMware Certified Professional (VCP), and CompTIA A+ and Network+.
Mauro is a recognized Microsoft MVP and has also been a long-time contributor to Windows Central.
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