well xonotic is quite a good game and use many recent techiques and is the same codebase for any OS, so if you wanna test OS vs OS is better to stick to software you can prove that behave the same in any given plataform.
if you payed atention to the article or even read it is a windows vs linux on nvidia blob not what gpu is faster, so i don't get what you whine??
doom3 is not a relevant test for an OS vs OS, if you actually put 3 neurons to work togheter you will see the reasons like:
* is closed source so you can't know for sure if it uses the same renderpath in both oses or any other typical dirty hack to gain more FPS that is not present within the other OS
* many driver especially on windows have many hacks to boost performance that trigger depending on the .exe filename that won't necessarily trigger on linux
* neither xonotic and especially doom3 will put any modern gpu to its knees
* this is not a game benchmark LOL is a driver level comparison of engines between 2 OSes, if you want game bench there are many specialized sites out there, you know
if you wanna reply do it technically i won't bother in answer stupid replys