Write operation using FileX and LevelX on NOR flash size is getting very slow?

Hi,

I am using W25Q64JV NOR flash of size 8MB on ST STM32U5A9ZJ board. On the flash I have created a file system using LevelX and FileX. I have enabled fault tolerant option in FileX. I am writing 128bytes of data every 500ms to a file. Initially the write operation is taking around 70-80 ms, however after some time (after around 3000 writes) the write operation occasionally is taking around 3-4 seconds. This is after every few writes. Following is the fx_media_format parameters I have used -

status = fx_media_format(&flashMedia, fx_stm32_levelx_nor_driver, reinterpret_cast<VOID *>(LX_NOR_OSPI_DRIVER_ID), reinterpret_cast<UCHAR *>(mediaMemory), sizeof(mediaMemory), "FLASH_DISK",

                              1,                  // Number of FATs

                              32,              // Directory Entries

                              0,                                                     // Hidden sectors

                              (0x800000 - 0x10000)/ 0x10000,// Total sectors minus one

                              512,                                                        // Sector size

                              8,                                                            // Sectors per cluster

                              1,                                                                          // Heads

                              1);                                                             // Sectors per track

Could you please let me know what I might to improve the performance? My goal is to complete the write operation of 128 bytes under 100ms in any circumstances. Thanks in advance.

Goutam