My roommate and I play games online together. We recently just got a new modem from charter a couple days ago which has drastically increased our download/upload speed based on speedtest.net results. However, when we play online now since the new router was installed my computer has extremely high latency whereas his remains low. This didn't happen before this new modem was installed. My computer is a 2011 Dell N5110 and his is an HP from 2-3 years ago. I am not sure what is going on. When I play the game away from my apartment's internet my latency is low. The new modem is a Netgear CG3000D.
We are paying for 18Mbps down/2Mbps up and getting about that.
My roommate is wireless. I have tried wired and wireless and both result in me having extremely high latency. And as far as firmware, it is up to date as far as I can tell when searching google for the model's firmware versions.