Hello and welcome to the forums Well the performance is pretty much the same,what are the other specs ? Also HD 4670M can handle current games @ medium setting well.
the 4670m is 1gb and the 9800m gts is 512mb the specs of the ati card don`t look so impresive. I had the 9800m gts 512 in gateway laptop 1920x1200 screen and played unreal turnament 3 on high settings with no problems I didn`t play it for to long as the heat output was realy high or should I say HOT. I also tryed NFS shift COD 4 GTA4 Anno SPORE Command & Conquer Crisis Personaly I think that the ATI isn`t as good... thx for your info