Unless you have a dedicated high speed fibre optic connection all of your own, your internet connection performance is not governed by the capabilities of you computer, as a computer. The slowest performing computer available can process data quicker than any normal domestic connection can deliver it.
Internet performance depends on how each link in a communication chain works. The chain is : computer to router; router to modem; modem to exchange; exchange to ISP's servers. The only one you have any control over is the first section. Wi-fi performance is affected by distance, materials between computer and router, and aerial position and quality - and these you have some control over. You have no control over the bandwidth your ISP is delivering unless it is significantly less than you were offered when you took out the connection contract - then you start nagging them or change provider (if that is an option).
Go to www.speedtest.net to run a check on the bandwidth you are being supplied with. For a one-off test there is no need to set up an account, but it is useful if you wish to log changes over time.