I wonder if this is related to that bare metal bios os post from a week or so ago. I asked the author why he used tty asm calls to print instead of calling int 10 directly and he said it was more efficient, but for different reasons.
> The method for printing uses an Intel UART driver to print characters
The spec (rightfully) says “(e.g. serial console)”, not “Intel UART driver”.
You cannot know what bare metal you’re running on. On some hardware it could be sending data out over Bluetooth, USB or WiFi because that’s the only connection to the outside world.
Rendering per string is better per string, but I'm not so sure how bad the difference is when it comes to UART but I doubt the system has enough throughput for the first implementation to matter.