7-zip extraction using multiple cores?

I have stuff.7z.001 to stuff.7z.007. They are big. Is there a way to 7z x in Linux to take advantage of multiple cores and speed things up? also, how does one run the 7-zip gui in rhel/centos 7 ? I have p7zip-gui-16.02-20.el7.x86_64 installed but I can't find a corresponding *7-zip gui* entry under the applications menu nor know the command line command to kick off the gui.