First and foremost, what is the make and model of your router and ofc the maximum allocated bandwidth for your ISP's subscription package? You also didn't mention the speeds you're seeing on your smartphone(namely speaking what the make and model of the smart phone is). Even if the router and your wireless adapter are(hypothetically speaking) above 900Mbps but your ISP's package is less than 150Mbps, you're not going to reach that magical 900Mbps mark no matter what you do.