Very slow SD card access since recent update to build 22581 - resolved

raymondb2000

Either it is related to write endurance, lack of drivers, or the bootloader not supporting a driver from another major revision of Windows.

Modify the bootloader with this Batch File (.bat) to support legacy peripherals (also try disabling "ABOVE 4G MIMO" in UEFI/BIOS.)

@ECHO OFF
SETLOCAL
REM Start Menu -> Run -> taskmgr -> File -> Run new task -> %SystemRoot%\System32\cmd.exe -> Check: Create this task with administrative privileges -> OK
REM NOTE: If you cannot find the correct entry, first run this: BCDEDIT /ENUM and replace {current} with {default} or whatever is listed below
REM Windows Boot Loader
REM -------------------
REM identifier              {current}
REM device                  partition=C:
BCDEDIT /SET {current} FORCELEGACYPLATFORM TRUE
MOVE NUL 2>&0

NOTE: One way around it which may not work, given there is no TRIM command for SD Cards, is to run the CLEAN command on the drive in DISKPART, and then reformat it (but you lose everything on the SD Card in the process. All you're really doing is wiping out the entire filesystem on that drive. Sometimes that can fix a filesystem issue with USB drives and SD Cards, but it's not always the case.) It's way easier to do other things first like modify the bootloader, or search for Motherboard drivers for the SD Card Controller. For instance, some SDcard readers require drivers to be installed which may not come with Windows 10/11:

https://www.realtek.com/en/component/zoo/category/card-reader-solutions-card-reader-controllers-software