In recent months, the attention of World of Warcraft players has been focused on the upcoming Shadowlands expansion and the recent update, which prepared the game for its launch. However, some users are finding time for other activities related to this popular MMO. This was the case with Reddit user samfishersam. Two years ago, he checked WoW's performance using the newly introduced support for DirectX 12. Now, the user decided to repeat the test and see if this time the 12th generation of DirectX will perform better than DirectX 11. He published the results on Imgur.
As in 2018, samfishersam decided to carry out a test with the help of so-called Flight Paths. They connect different zones in WoW, and every journey using them is almost the same. This, together with the ability to quickly repeat the flight, makes the Flight Paths ideal for benchmarks. The user chose two routes from the Isle of Fangs in Zuldazar: one leading to Tortaka Refuge in Vol'dun and second to Forlorn Ruins in Nazir. To be sure, after each test samfishersam completely closed the client and restarted World of Warcraft, and after switching on the game waited two minutes for it to fully load all elements. Additionally, the user used ProcessLasso app to automatically assign 8 CPU threads to the game instead of the default 4. All this to eliminate factors that could distort the results.
WoW DX11 vs DX12 - test results
Just like two years ago, DirectX 11 now has a higher maximum frame rate than its younger brother. That's the only thing both tests have in common. Not only is the difference much smaller than in 2018, but in all other respects, DirectX 12 did better than DX11.
More importantly, however, DirectX 12 proved to be much more stable than DX11. Only 1% percentile FPS on the route from Zuldazar to Vol'dun was minimally in favor of the older API - on the flight to Nazmir the advantage of the DX12 was significant. However, with with 0.01% percentile the older API was twice as bad as its successor, which in practice means more stutters, delays, etc. DirectX 11 had drops to about 30 fps, while the 999th percentile was over 60 frames per second for DX12. Things look a bit worse without automatically assigning 8 CPU threads, although even then DX12 was more stable than DX11.
To sum up, if we play World of Warcraft, we finally have a reason to switch to DirectX 12. Or rather, "another reason" - the recently revealed system requirements of upcoming games (for example from Ubisoft) increasingly often mention, if not as necessity, the a recommendation to use DirectX 12.