New Zyxel Modem Slower Than Old Zyxel Modem

bugi

So i decided to change my old P-660-TWx modem because i needed to reset my modem 5 times a day and the process took 5-6 minutes everytime. So i bought a VMG3625-T20A. It is stable and all but can't connect to it upstairs but thats ok too. I can buy a router for that. But why did i lost speed? How can my 10+ year old modem can give me 16.5Mbps speed but this new modem can only give 13Mbps? My speed is already slow and this much loss is quite a lot on this speed. What is the problem? Is there a solution? Hope you can help me. Thanks.

 Update: Downloading with 980kb now. Just great.

bugi

And i would like to add that i can't even search anything on google if im downloading something. I didn't have this problem with my old one. I was able to even watch youtube videos without losing speed. I'm really lost here.