So I have internet at 12mbps download and 1mbps upload according to speed test with a ping of 34.
I am experiencing horrible lagging on diablo 3 in the day time, but not in the evening. I just moved and last night was the first time I used the internet at my apartment to play D3. I can watch netflix in HD no problem. So whats up? I don't even know what my issues are any help?
It could be network congestion to whatever server you connect to for D3, but going to netflix takes a different route (think roads, you have multiple ways to get from point a to b, but some are faster). You can't really do anything about the congestion unless the server providers on the way upgrade the gear.
Click on Start, type cmd in the search field, and select command prompt, then type tracert -d to the D3 address if you know it, then repeat tracert -d www.netflix.com
You will be able to see what and where you are getting your lags at...