N300 wifi Performance Issues

[arrrbee]

The internet is too slow. When you plug the computer in via ethernet, I get 100 MBPS, which is what I'm paying for. But over the wi-fi my top speed is about 20 MBPS. During the day when we're using multiple devices, the internet slows way down and becomes unusable, less than 5 MBPS. What can I do to improve this?

[TheEther]

Let's tackle the Wi-Fi problem first.  What kind of Wi-Fi adapter does your computer have?  If it only supports 802.11g, for example, then 20 Mbps is pretty much the highest speed it can achieve.  

BTW, for future reference, Wi-Fi and Internet speeds are usually expressed in Megabits per second and this is abbreviated as either Mb/s or Mbps. We distinguish this from Megabytes per second, which is abbreviated as MB/s.  MBPS is never used as an abbreviation because it's ambiguous; is it Megabits or Megabytes per second?