I don't know where you are, so I will answer for both telekom technologies.
All you have to do is look up the technologies behind the 3G logo, you have 3G, UTMS, HSDPA, HSPA+ and CDMA/EV-DO.
CDMA is in the USA/Canada/Mexico/Asia. It maxes out at 3mpbs, average real-world speed is 1-1.5mbps.
The fastest reported speed in Europe/USA for 3G is about 30-42 mbps. HSPA+ and LTE are supposed to break past 50mbps.
The USA and Europe is on 3G/UTMS.
I have seen 10mbps and 30mbps data rates here in Austria. But the catch is that you have to be right next to the tower for it to be that fast.
Average data rate is 2-5mbps here in Europe.
What is your carrier? What is your data limit? What do you use your phone for?