The Remastered version, which the CODEX release is based on, provides a massive graphical leap over the 2007 original:
No article using "callofdutymodernwarfareremasteredcodex better" can ignore the elephant in the room: You cannot play official multiplayer. callofdutymodernwarfareremasteredcodex better
Adjust these specific display settings to drastically improve your framerate: The Remastered version, which the CODEX release is
: Use this for the best raw performance and lowest input lag. The Remastered version