The problem is you upload speed =(. When you are streaming, you are sending a lot of data, so your ping will get highter. You may call to your internet service provider (ISP) to ask if they can raise your upload speed.

Also try to decrease the quality of your stream. By quality I mean, for example, from 720p to 480p.

High ping on games while streaming
A former coworker did something to top that whenever it runs as root the data is sorted by MEM usage instead of the default CPU usage. According to multiple searches, the man page and even the options within the top console itself (O), just pressing k it should be sorted by CPU, but instead when I hit k it asks me for a pid to kill.

So how can I get back default sorting to CPU?  
