Speed UART transmissions using HAL_UART_Transmit_IT() vs I2C

[JLope.11]

I detected that transmitting 68 characters using RS232 at 460800hz takes 30-32000 tics to micro running at 480Mhz (HAL_UART_Transmit() takes 10 times more).

Is there a method to disturb less to micro to make that transactions, perhaps using DMA?

Is better use I2C, and is possible to use printf to I2C?