GameXplain shows Breath of the Wild running side-by-side in both portable and docked mode. The end result is something quite interesting, as the portable version runs better. Using 720p as it’s resolution, the game runs at a stable 30FPS with little to no drops; an impressive feat considering it’s a large open world. But when you crank that resolution up to 900p when docked, some issues come up.
The footage GameXplain provided shows that the frame rate takes a heavy hit into the low 20’s when exploring areas with lush grass, indicating the stream of data or too much GPU usage causing the slow down. It wasn’t tested in docked mode when locking the Switch’s native resolution is set to 720p however. Nintendo will likely either patch a fix or encourage you use the 720p resolution/portable mode for better frame rates.