The LattePanda Mu is a petite yet powerful x86 compute module
And it even has a functional PCIe slot!

The DIY project-building ecosystem is largely dominated by SBCs and microcontrollers. However, there’s a third category of tinkering devices you can integrate into your computing projects. By that, I’m referring to compute modules. For the uninitiated, these are tiny boards housing the processor, memory, and other bare minimum components while leaving the IO ports and power connections to an add-on development board.