I just ran the game and apparently the defaults are 800x600 which would explain why in my last benchmark the FPS is higher on the retail vs. the "FLT" release (FLT was @ 1024x768). My settings are:
Radeon 9800NP flashed and o/c'd to 400.5/350
1024x768x32 - No AA/AF
VSynch - 85Hz
Textures - High
Particles - High
Specular - Yes
Shadows - On
Decals - On
800x600Date / Time: 10/3/2003 12:12:35 AM (48500375ms)
3200MHz, 1024MB, 128M ATI Radeon 9800 PRO (DeviceID=0x4e48) Driver=6.14.10.6378 Shader=2.0
C:\Halo\HALO.EXE -timedemo -use20 (Version=1.0.1.580)
Frames=4700
Total Time=98.72s
Average frame rate=47.61fps
Below 5fps= 5% (time) 0% (frames) (5.247s spent in 9 frames)
Below 10fps= 5% (time) 0% (frames)
Below 15fps= 5% (time) 0% (frames)
Below 20fps= 6% (time) 0% (frames)
Below 25fps= 6% (time) 0% (frames)
Below 30fps= 7% (time) 1% (frames)
Below 40fps= 21% (time) 11% (frames)
Below 50fps= 53% (time) 42% (frames)
Below 60fps= 85% (time) 79% (frames)
Memory used Max=161MB, Min=131MB, Ave=149MB
1024x768Date / Time: 10/6/2003 4:53:20 PM (110286109ms)
3200MHz, 1024MB, 128M ATI Radeon 9800 PRO (DeviceID=0x4e48) Driver=6.14.10.6378 Shader=2.0
C:\Halo\HALO.EXE -timedemo -use20 (Version=1.0.1.580)
Frames=4700
Total Time=120.95s
Average frame rate=38.86fps
Below 5fps= 14% (time) 0% (frames) (16.964s spent in 12 frames)
Below 10fps= 14% (time) 0% (frames)
Below 15fps= 14% (time) 0% (frames)
Below 20fps= 14% (time) 0% (frames)
Below 25fps= 17% (time) 2% (frames)
Below 30fps= 29% (time) 10% (frames)
Below 40fps= 46% (time) 26% (frames)
Below 50fps= 64% (time) 45% (frames)
Below 60fps= 91% (time) 83% (frames)
Memory used Max=161MB, Min=130MB, Ave=149MB
As others have pointed out this "timedemo" tool isn't a true benchmark of the game as it includes load times where there is no video being displayed. They are supposed to fix this in an upcoming patch.