I would have thought you would have got a very much higher figure than that judging by recent reviews.
Don't fret though. My Celeron 400MHz system used to reach about 550 and a recently installed Pentium III 550MHz (Kaimi) notched up a gasp inducing 1053.
I've bettered that since to 1055 after installing DirectX 9.0c...:-)
Mind you I don't play games.........