I am using the stock firmware with the WRT1900AC from Linksys, so no open source funny business. (yet)
Currently have TWC's Ultimate Package providing 300Mbps down and 20Mbps up. I am renting their modem, because I was having consistent errors with my own purchased Arris modem and holding a firm up and down.
When I am hardwired into my laptop after the router, I pull full speed. When I disconnect and connect on WiFi using a laptop with an AC networking card in it, it pulls full speed next to the router.
Here is my actual problem. After going into my upstairs, which is not terribly far from my router, signal strength at the OS level still reads at full. However, a speedtest.net tells me I am pulling .25 Mbps down, and still hitting 20Mbps up. I do not have concrete or lead walls, just plaster and wood.
As I inspect further, when I go upstairs, it has transitioned from the 5GHz antenna to the 2.4GHz antenna, and the RSSI goes from -21dBm to -62dBm
How much of an impact does RSSI make on connection speed, and could there be something else physically wrong with my router? Please lend me your brains, and be gentle if I am missing something glaringly obvious.