Your desktop gets so much higher because you have a DirectX8 compliant card. Every laptop GPU is only DX7 compliant. Jeeze, I want to smack you and tell you to be quiet.
My Inspiron 8000 with a 1000MHz (100 bus

) processor with a 32 meg GeForce2Go only gets ~2000 3dmarks with the new Det4's. I'm so angry I didn't wait 6 months to get a laptop.. I REALLY wanted a mobility Radeon.