My camera is taking longer to write data to a memory card.

We recommend that you perform full formatting (physical formatting) on the camera before shooting important events.

Residual data accumulates over time as data is repeatedly written to and erased from the memory card. The erasure of this residual data takes place on the card internally when new data is written, and this can slow down the write speed. If continuous shooting become slower or errors occur when recording video, the cause could be the effects of residual data.
Performing full formatting (physical formatting) completely erases all the residual data, so it allows you to eliminate the problem.

Sony cameras allow you to switch from ordinary quick formatting to full formatting on the menu screen used for formatting. Particularly before shooting important events, we recommend that you perform full formatting on the camera.