I'm a little late here but let's clarify some things because there's so much wrong:
- Vanilla CoD was based off Return to Castle Wolfenstein which was in turn based off Quake 3 (ID Tech 3 essentially)
- Code base essentially became more Infinity Ward than id although many things persisted like the exact same console commands, demo recording and playback, engine quirks, etc.
- As far as we can tell, Treyarch got the engine at some point from IW and it 'branched', though as above most functionality was intact
- Physics in ID Tech 3 was indeed tied to framerate. You can 'set' the 'FPS' cap (com_maxfps) to integer divisions of 1000 which affected both physics calculation and framerate.
- For whatever bizarre reason (related to rounding), 125, 250 and especially 333 FPS your character in the game had a very definite physics advantage completely decoupled from the netcode tickrate (how often the server and clients communicated) due to physics-side calculations
- Q3A eventually patched the game so that the physics calculation always happened at '125FPS' regardless of your framerate. Quake Live launched without this issue.
- For whatever reason, Infinity Ward never applied the same fix. I'm guessing by the time it became a big issue (around CoD4) the series was more of a console game than a PC one.
- CoD4
DID NOT have a max FPS (well, technically 1000). Neither did World at War.
- The professional CoD4/promod scene standardized all play to 125 or 250fps. 333 was considered flat out cheating and an actionable offense.
- MW2 capped FPS for the PC version to 91. Why this arbitrary number? It's the 1000/11 divisor (90.90909090) and essentially the engine hard-wired com_maxfps to 91. For whatever reason Infinity Ward decided this was the 'most balanced', despite professional FPS revolving around id Tech 3 had already basically agreed on 125FPS at the time. I guess IW figured this was an easier band-aid than following in Q3A's footsteps and ACTUALLY FIXING THE ISSUE, especially since it would have meant that the console and PC versions of CoD became fundamentally different mechanicswise. (You could
pull off jumps in CoD4 PC you could never on console and this was a skill SMG position promod players were pretty much expected to have)
You can read more about how much the game breaks at 333fps here:
http://wiki.modsrepository.com/index.php?title=Call_of_Duty_:_A_Study_on_FPS
- You jump significantly higher
- You jump further
- You take less fall damage (lol)
- You can move at a higher speed before footsteps trigger