points by glouwbug 3 days ago | 0 comments
At 8mhz? I'd imagine it rivals at least the Pentium III
[–] pavlov 3 days ago
[–] vardump 1 day ago
The average scalar (=integer) instructions per cycle is pretty comparable between Pentium III and Xtensa LX6, the original ESP32 CPU representing the worst case.
While P3 is superscalar, it could only execute about 0.9 instructions per cycle on average. Of course you can optimize for it and get better results in certain cases.
Most Xtensa scalar instructions take just 1 clock, branches 3 for taken, 1 for not taken. So 0.7-0.8 instructions per clock is a reasonable estimate. Assuming of course code is executing from SRAM.
Xtensa's FPU is slow, and it lacks divide and square root instructions. Clock for clock, P3 probably outperforms it by 3-4x. It also lacks 64-bit floats.
[–] pjmlp 3 days ago
Probably, I was use this example because I feel youngers can't imagine how much we could do with such MS-DOS class computer, even within its limitations.
So naturally an ESP32 can do so much more.
The Pentium III was a superscalar core that scaled up to 1.4 GHz. This microcontroller is max 240 MHz and does less work per cycle.