There are quite a few game engines available these days. Unity stepped up its game and Epic Games, Crytek, Amazon, and others entered the market with various free-to-start licensing options. Back in the early DirectX 11 days, UNIGINE released their popular Heaven benchmark to promote their engine, which had a relatively affordable, up-front fee. (I don’t remember what it was at the time, but the engine currently starts at $1495 USD, albeit royalty-free.)
Available up to 8K60, because lol why not?
Today, they have released a new benchmark, called Superposition, which focuses on two things: VR and GPU stress testing. The setting is some old-timey physics lab, and it includes some minigames to keep you entertained after you determined that your overclock is stable and your performance is assigned some value. According to Phoronix, UNIGINE has been looking into Vulkan, but they haven’t added it to the engine yet. On Linux, you’ll be using OpenGL 4.5, but Windows has a choice between that and DirectX 11.