I've just installed a Linksys WRT1900 AC router and a Linksys 4008 8 Port Gigabit switch.
My setup goes Cable Modem -> Router - > Switch and all wired devices hang off the switch.
I noticed the internet speed on my pc (Directly wired to switch) has dropped from around 200mbps to 20mbps as soon as I moved to the new equipment. Just as a test I plugged the PC straight into the modem and the speed returned to 200mbps. I then put it back in the switch and it was still reporting 200mbps on speedtest.net. I then moved some cables around to different ports and it dropped back to 20mbps.
At this point I decided the switch may be faulty so removed the switch and plugged everything straight in to the router. Still 20mbps. I moved the PC cable to a different port on the router and it then went back to 200mbps.
My internet connection speed it normally a solid 200mbps and does not change. There definitely seems to be some sort of issue with ports on the router/switch but it seems random or at least I can see no pattern. I've tried swapping network cables and can see no indication a given cable is faulty.
I can't imagine both the switch and router are faulty so my question is what could cause this behaviour?
Edit : The router LED's are indicating all devices are connecting at 1000mbps
Edit 2 : One thing I've noticed is if when it's slow I disable the adapter in Windows and re-enable it then all is good. Could it be that me changing ports and not releasing/renewing the ip causes that could cause speed issues and the disable/enable fixes that?