4 ms·
> I always wonder about how the hell DOOM ran at 30 fps on a 33 Mhz system. It didn't. It ran at ~25 FPS on a 66 Mhz 486 and only ~15 FPS on a 33 Mhz system. I
by Narishma 5y ago
> I always wonder about how the hell DOOM ran at 30 fps on a 33 Mhz system.
It didn't. It ran at ~25 FPS on a 66 Mhz 486 and only ~15 FPS on a 33 Mhz system. It needed a Pentium to reach half the refresh rate, which was 35 FPS at the time.
https://youtu.be/HNlcZetLzY8?t=209 https://youtu.be/HNlcZetLzY8?t=209
- Sohcahtoa82 5y agoThat's still only ~41 clocks per pixel. I wonder how many clocks multiple and add instructions took on a 486.
- bonzini 5y agoYou don't need to multiply in the inner loop if you draw along a constant-z line (which is easy to do if the walls are all horizontal or vertical).