Slave pens at 400k/hour non-rested with a sub-standard group that could be easily improved to almost 700k+ an hour. I'm also 95% sure this is how athene got 60-70 so fast, as you can see in one of his movies he dings 70 in SP. This is as easy as it gets and before people start calling fake private server blah blah, go try it yourself.

Also, if you don't like the music, mute it.

Enjoy - Rumiah..