[FpUser]

Curious what factors limit clock to 8kHz.

[sbierwagen]

https://www.quora.com/How-is-transistor-density-related-to-c...

[errcorrectcode]

Worst case propagation delay.

[FpUser]

This does not make any sense. I can get way better delay / frequency wise on long USB cables. Something here does not compute.

[errcorrectcode]

Then you don't understand digital logic or how processors are designed, single cycle or pipelined.