Shekkel

Hey guys I have a doubt... Im having BSNL 750UL plan which is 512kbps..I got the default BSNL UT300R2U modem and im getting a speed of 50-60kB/s. My friend took the same plan few days before and he called me to his house on asking how to download games and movies. He had a black color modem which is somemore bigger than mine. And while downloading one of the game it was goin in a speed of 100+kB/s and i was amazed.. Is it because of the modem or some line problem with mine??? Please reply, so that i can buy a new modem...