Performing a full format on SDHC media may take a long time to complete in Windows 7

Applies to: Windows 7 UltimateWindows 7 EnterpriseWindows 7 Professional

Symptoms


Consider the following scenario:
  • You have Windows 7 installed on your computer.
  • The computer has either an internal or external memory card reader that supports SDHC media.
  • You insert an SDHC memory card into the reader.
  • You perform a full format of the SDHC card by opening the Format Removable Disk window and deselecting the check box next to “Quick Format“.

In this scenario, after clicking on Start to begin the format, you will notice that the time taken to complete the full format will take considerably longer than it did previously with Windows XP.


Cause


There was a change in Windows Vista and newer operating systems that when performing a full format, the process will zero out every sector.  This can take a considerable amount of time with larger capacity SDHC cards.  With Windows XP, the sectors were not zeroed out when performing a full format.


Resolution


If a full format of the SDHC media is not needed, it is recommend that you use the default Quick Format option.


More Information


As an example, a 32GB SDHC card was tested and it took approximately 45 minutes to perform a full format in Windows 7. Using the same SDHC card in Windows XP SP3, it took approximately 1 minute to complete a full format.