A hot potato: For many subscribers to Google's Stadia Pro, the thought of being able to play Doom Eternal at a true 4K resolution was enough to hand over $10 per month. But according to id Software, the game won't live up to its promise.
At the Game Developers Conference in 2019, id Software's Marty Stratton said that Doom Eternal "will be capable of running at true 4K resolution, with HDR color at an unrelenting 60 frames per second" on Stadia. According to the game's launch details, however, one of those claims isn't true.
While Doom Eternal on Stadia will run at 1080p@60fps on HD displays, and support HDR, it will up-sample to 2160p from 1800p@60fps on 4K displays. While that's still better than 1440p or up-scaling from 1080p, it means playing the FPS on Stadia will offer the same level of performance as the Xbox One X. Google had said Stadia's GPU performance was better than Microsoft's console and the PS4 Pro combined.
Other Stadia games have similar resolution issues. Red Dead Redemption 2 won't natively render higher than 1440p and is updscaled to 4K, while Destiny 2 renders natively at 1080p and is upscaled but doesn't reach 4K.
It was only last week that Stadia finally started rolling out 4K streaming support on the web---it had previously only been available to Chromecast Ultra users with a television.
If you're playing Doom Eternal on a PC, check out the minimum and recommended requirements here.