[anshargal]

I wonder if there is a simple chip, similar to the 4004, 8080, or Z80, that can run at modern high frequencies — 4–5 GHz, or even higher due to its simplicity? Not much of a practical use, but it could be fun for emulation projects. 100x slower with emulation - still fast enough for retro platforms.

[dmitrygr]

RP2350 can hit 400mhz on two cores without much effort. 800MIPS of total power, if you can parallelize your emulator

[tails4e]

An FPGA could 400mhz with a bit of effort, 100mhz easy.