The Nintendo Switch has a dynamic GPU scaling feature for games when they're docked and when they're undocked. This means that different games perform differently under certain conditions, like The Legend of Zelda: Breath of the Wild.
Richard Leadbetter, chief engineer at Digital Foundry, did a thorough examination of the technical performance of The Legend of Zelda: Breath of the Wild. In their benchmarking tests they were able to go over frame-rate, resolution and the differences between the dock and undocked versions of the game.
After testing more than 40 minutes worth of compiled footage, Leadbetter explained...
720p pretty much locked 30 frames per second when you're playing in handheld form and 900p when you're playing docked with the HDTV
They mentioned that the Wii U version suffered from some major frame-rate drops, which they mentioned that it oftentimes averaged between 20 and 30fps. They also mentioned that the Wii U also suffered drops all the way down to the teens during heavy alpha and post-processing effects.
They mentioned that there's a fascinating rift in how different games scale depends on portable and HDTV modes. For instance, while The Legend of Zelda: Breath of the Wild scales from 900p in the TV mode down to 720p in the portable mode, Mario Kart 8: Deluxe scales from 720p in the handheld mode up to native 1080p at 60fps in the TV mode, which is extremely impressive.
For reference, Ryse, a launch title on the Xbox One, runs at native 900p at 30fps, which is the same as The Legend of Zelda: Breath of the Wild.
So in terms of scaling, you could say that Breath of the Wild represents the Switch's first generation software capabilities in the same way that Ryse represented the Xbox One's first generation software capabilities.
There are a few things to keep in mind in regards to the actual technical aspects of the game. There's temporal aliasing and dynamic, streaming texture filtering. What this means is that the textures upscale through a streaming filter as you move through the environment, and that was something they noticed while playing, calling it "poor". It is rather obvious seeing the ground textures load into memory and filtering in real-time (somewhat slowly). Increasing anisotropy on the fly with the slow filtering can be a bit jarring, but it isn't that awful. You can see it in action with the video below.
Overall they mention that the game runs quite smoothly on the Nintendo Switch, and definitely offers the more stable experience compared to Breath of the Wild running on the Wii U. Unfortunately, due to how graphics-intensive the game is, you're only going to get about three hours of play when playing portable mode on the battery alone. So that's something to consider as well.
Gamers will be able to get their hands on the newest Legend of Zelda at the beginning of March with the launch of the Switch.