It is suggested that on Linux, GPU be found with the command lspci | grep VGA. It works fine on Ubuntu but when I try to use the same on CentOS, it says lspci comma
lspci | grep VGA
lspci should be in the package pciutils.
you could do this with dmidecode but as your not an admin you probably cant do this nor installing the pciutils package.
IF there is a Xorg on this system then it should be easy:
grep Graphics /var/log/Xorg.0.log