Maximize FileX write speeds

Question

I am using FileX to write JPEG data into an SD card, using an STM32 chip. My project is trying to maximize the JPEG resolution/framerate, so I need my FileX writes to execute as quickly as possible.

My current setup has 38,400 bytes of data available for processing/writing every 5ms, so I'm writing at most 38,400 bytes per call. But so far I'm only able to get each write to take around 8ms to execute. Using the tips from the official FileX docs, I've already ensured the source buffer being on a boundary and the size being evenly divisible. My SD card should be able to handle very high speeds (it has video speed class V30 i.e., min write speed of 30MB/sec), and I've configured my microcontroller's SDMMC clock to 48MHz (I believe that's the fastest).

I would like to ask for suggestions on what other things I can look into to speed this up. Any thoughts would be appreciated; thank you in advance!