Screen tearing Xfwm 4.13

I keep having screen tearing on my mac mini 2012 intel graphics Xubuntu 17.04 ppa:xubuntu-dev/xfce4-gtk3 According to this article, it says xfwm 4.13 finally eliminates screen tearing. https://iwf1.com/review-xfce-4-13-desktop-environment-a-noticeable-difference-from-its-predecessor/ How can I check if it is enabled? I tried enabling sync_to_vblank but it made no difference. This is xfwm4 version 4.13.0git.7d9e6ced (revision 7d9e6ced) for Xfce 4.12 Released under the terms of the GNU General Public License. Compiled against GTK+-2.24.31, using GTK+-2.24.31. Build configuration and supported features: - Startup notification support: Yes - XSync support: Yes - Render support: Yes - Xrandr support: Yes - Xpresent support: Yes - Embedded compositor: Yes - Epoxy support: Yes - KDE systray proxy (deprecated): No