Unreal Tournament 2003

The 200MHz clock speed boost isn't nearly enough to help the Pentium 4 overtake the Athlon 64 in UT2003. The Prescott and Northwood scale almost identically here, tracking very close to one another in performance, as well.

Quake III Arena

Wolfenstein: Enemy Territory

The Athlon 64 again outdoes the P4 in Quake III and Wolf: ET. Notice how Prescott seems to pull away, ever so slightly, from Northwood in Quake III as clock speeds ramp up.

Tom Clancy's Splinter Cell

Northwood and Prescott perform nearly identically in Splinter Cell, but neither can catch even the lowest model Athlon 64.