New Lag in Coop

So I recently starting getting lag in COOP play, all my ports are open and my computer plays fine on high graphics in single player. Anyone have any ideas?
|||Make sure your coop partner doesn't lag. Coop games will connect both players to each other and if the routing isn't ideal, you will experience lag.
|||He says he doesnt lag
|||May I ask what you and your friends' locations are? And what connection speeds do you both have?
|||We are both are in New Jersey, can I know how I can check the speeds?
|||

http://www.speedtest.net/

Choose the server closest to where you live or just choose the default recommended server. It will test your downstream and upstream and create an image with the results for you.

ps. Flash is your browser is required.
|||http://www.speedtest.net/result/1453599625.png|||Try turning down your graphics settings dpwn, if one of you is getting performance related lag it will effect both of you.
|||

It doesn't seem to be related to your connections speeds. The poster above is correct, if one of you lags the other person has to wait until the game synchronizes.

Might be your friend who's causing the lag, but it's difficult to determine without him posting here.

http://www.pingtest.net/

To check for latency issues.

|||

http://www.pingtest.net/result/46011980.png

I turned all graphics on low and it seems any coop I play I lag, but I dont lag in single player.