I've just upgraded from a dual P3-1000 to a P4-2400/533 (a natty little Shuttle system) and am seeing only a modest improvement in AH offline (haven't tried online yet). I run AH at 1600x1200x32.
Both systems use EIDE and Gf4-4200 video cards. Drivers are Detonator 43. Both machines have 1 GB RAM. Both systems run XP Pro and are fully updated as per WindowsUpdate. Neither machine is overclocked.
In AH, I load the Trinity map, and take a C205 to an enemy vehicle base. I get 60-80 fps along the way, but this drops to 50-60 fps when attacking, and < 30 fps when I fly through the smoke.
If I enable Quincunx FSAA, those figures are cut by 2/3.
I've tried 3DMark 2003: my P3-1000 scores 1009, which is about right, but my P4 only scores 1296.
I've read about nVidia's concerns, so I benchmarked UT2003 at 1024x768 (fresh install and unpatched - haven't Epic heard of DVDs?), no tweaking, and my P3-1000 scored 82 on Flyby and 31 on Botmatch, whereas my P4-2400 scored 136 and 56 respectively.
I've gone through the BIOS tweaking where necessary - e.g. telling the computer that the memory is DDR333, not DDR266 with little effect.
I've got the usual system tray stuff running
Am I getting correct results? If not, how can I increase them?