I build a linode VPS with CentOS 7 , in CentOS, the Gnome desktop and vncserver are installed . then I connect with VNCviewer remotely from my local PC. the screen can appear but whatever I do such as surfing web,see video from youtube, the screen refresh very very slowly,just like slide show. I just want the screen shows normally just like my local screen. How can I achieve this goal? Pls someone friends give me some advice? much appreciation about that.