How Many Computers Are in Your Computer?
The cpu also has typically multiple independent CPUs to control things like power saving and turbo boost.  Modern intel cpus have multiple 486-class CPUs, one for this, one for the ME, and one that vendors can use that has SMM access (which is as scary or more so than the ME).<p>OpenPOWER is pretty neat because you can actually see what commercially relevant implementations of these firmwares look like <a href="https://github.com/open-power/occ" rel="nofollow">https://github.com/open-power/occ</a><p>A lot of NICs are also completely based on multiple general purpose MIPS cores like Broadcom and Mellanox.  The most common SAS HBA from LSI/Broadcom was a PowerPC SoC.  And SATA/SAS drives are running multiple ARM Cortex M series MCUs for the bus interface, drive geometry, and FTL in the case of flash.<p>The BMC (IPMI) is also a self sufficient ARM computer.