I got 13600 on 3dmark06 with my rig, is it good or not for the setup? Amd Phenom IIx3 720 oced to 3.2 Ghz
gigabyte ma790x mobo Sapphire Radeon hd4850 1Ghz gpu arctic cooler pro 7 OCZ ddr2 1066 2x2Ghz ram
That score is good for your setup, no worries.
Someone with an X4 will score a little higher, 3Dmark06 tends to favor more CPU cores, the CPU part of the test is pretty intense. But unless you are playing a game that can utilize more cores, in real life there would be no advantage to the higher score.