Does a ethernet switch help with streaming/gaming?

I have a new netgear n600 router and for the most part its pretty good. just every now and then the internet seems to be slowing down. now before we got our new router my dad accidentally bought a gigabit ethernet switch that said would get up to 10x faster speeds than fast ethernet for video streaming and gaming and video conferencing. we hooked it up as if it were a router and it did seems to stream videos really well and quickly as if i were plugged in right to the modem if not faster. the only thing to that was it only let 2 computers connect to the internet at one time. according to the local connection it says i get 100mbps when using the n600 router when it says it gets speeds of up to 300+mbps but with the ethernet switch it said i was getting 1gbps and although it wasnt 10x faster it was definitely quicker when it game to the internet in general. was this because it was only connected to the modem so if i were to hook up a gigabit ethernet switch to my n600 router would i not get that same performance?