> And if they support external RAM, its MCU-protocols like SPI-RAM (which rarely goes much further than 1MB) That's not generally true. A lot of higher-end STM

> And if they support external RAM, its MCU-protocols like SPI-RAM (which rarely goes much further than 1MB) That's not generally true. A lot of higher-end STM32 MCUs have support for external SRAM/SDRAM -- I have a STM32H7 board on my desk with 32 MB, for instance. (Support for memory-mapped SPI/QSPI/OSPI RAM is actually less common.) You're correct that internal SRAM is typically no more than 1-2 MB on even the largest parts, though.