The comparison that I was aiming to make was comparing a "busy wait blocking" implementation, e.g. sending one byte at a time, until the byte has been sent, which is typical for bare metal embedded systems (that don't use some kind of DMA or concurrency like threads or tasks).
In this case, your CPU would be left spinning for an equivalent amount of time to the line rate of the serial port, if you were busy waiting for data.
As a note, you can click on the time stamp of the child post, and respond directly there.
> since I can't reply to the child I'll just say this: I don't like the math you used, I feel like it's making a point that shouldn't be made in a place where it doesn't need to be made. Of course it's going to be dog slow if you're busy waiting. Wtf? I guess I will just leave it at that.
The entire post is about reducing the CPU time necessary to receive data from an external interface, like a serial port. The following paragraph states:
> Instead of making our CPU waste all of this time waiting around, we allow the hardware to manage the simple sending and receiving process, allowing our CPU to either process other important tasks, or go into sleep mode, saving power or battery life.
The intent for this example was to illustrate the difference between busy waiting and DMA. It is not uncommon on microcontrollers to only have a FIFO depth of one byte, which means if you aren't using interrupts, DMA, or threading, you will lose that data.
https://ferrous-systems.com/blog/lock-free-ring-buffer/
Could you explain what you think the misunderstanding is, and what the consequences of that misunderstanding are?