A 166 MHz Pentium is massive overkill for RCT. Consider that just a 100 MHz Pentium could render Quake locked at 60 fps, and a 166 MHz Pentium will have been a later and much improved version which also had MMX. The 233 MHz Pentium with MMX ran the original Unreal with coloured lighting and everything.
BTW I also remember the cache sizes of all these chips and wrote mostly in asm on them. Most people who were good at asm coding didn't stop because it took too long (you can always focus on just the hot loops), we stopped because we started getting our asses handed to us by C/C++ compilers.
Finally, just because asm coding provided sufficient performance, doesn't mean it was necessary, and it's of course possible to write arbitrarily slow asm code too (like a bubble sort in asm vs quicksort in C).
BTW I also remember the cache sizes of all these chips and wrote mostly in asm on them. Most people who were good at asm coding didn't stop because it took too long (you can always focus on just the hot loops), we stopped because we started getting our asses handed to us by C/C++ compilers.
Finally, just because asm coding provided sufficient performance, doesn't mean it was necessary, and it's of course possible to write arbitrarily slow asm code too (like a bubble sort in asm vs quicksort in C).