MCBSTM32MP157
The most powerfull evaluation-board in use so far has a dual-core Cortex-A7 running at 800 MHz and a Cortex-M4 running at 209 MHz.
This board has 1 GB RAM, much more than other boards.
A main-application is using the A7-cores with openSTLinux,
you will get a complete powerfull Linux-host using keyboard and mouse as input-devices.
Initialy for testcases only I have compiled Stockfish-engines for this system.
This is working so well that I have this in use frequently.