im using archer c7 v2...bought January of 2016...is it still under warranty?

here's the problem...

1. during heavy dload and upload (torrent/speedtest) the wifi connection seems like no internet connection for 30-60sec and keep doing that until heavy load are off....the wifi connection are still there but there's no internet..what seems to be the problem?

2. wifi speed only 200-250mbps on 5ghz(stand next to the router) while it suppose to be 300-500mbps

if under warranty i want to send in for checking...if not...can i send it for repair?

i have this problem way before the turbo upgrade...so just asking whether still in warranty or not n if not can i send it for repair...if the cost to repair is cheap...i can sell it to my friend after the repair and get a new better one...