Nintendo released version 1.1.1 of The Legend of Zelda: Breath of the Wild for the Nintendo Switch to "make for a more pleasant gaming experience." That's not a particularly descriptive patch note, but early impressions show that noticeable frame rate issues have been mitigated, if not totally resolved.
We noted in our hands-on with the Switch that, although we didn't measure Breath of the Wild's frame rate, dips below its target 30fps were easily seen with the naked eye. To avoid story and gameplay spoilers, we'll say only that the frame rate tended to drop most often in specific locations or when combat involved more than one enemy. It certainly didn't ruin our experience with the game, but it was definitely notable, and sometimes distracting.
Revisiting some of those locations or entering combat with patch 1.1.1 installed showed that at least some of the issues have been addressed. We didn't spot any drops in some places, and in others, we noticed fewer stutters than we did before. Note that this is with the Switch in TV mode; playing Breath of the Wild in handheld mode resulted in very few drops even before this update, perhaps because it renders at 720p instead of the TV mode's 900p.
These problems didn't take us by surprise. Breath of the Wild started development as a Wii U game, and as the directors' presentation at GDC 2017 alluded to with a mock email instructing them to prepare the game for the Switch's launch, the dev team didn't have much time to optimize for the new hardware. (Nintendo's been surprisingly open about Breath of the Wild's development--it even published a multi-part documentary about the process.)
You can install version 1.1.1 of Breath of the Wild for Nintendo Switch by launching the game from the console's menu, which will automatically start the download process, or by pressing the - or + buttons on the console's controllers, selecting the Software Update option, and choosing Via the Internet. The patch is free, so you don't have to worry about buying the Expansion Pass, which offers access to current and upcoming downloadable content.
Nintendo also released this patch for the Wii U version of Breath of the Wild, but we haven't been able to test that version of the game, so we can't speak to its performance before or after the update. The performance update on both consoles highlights Nintendo's commitment both to its previous console--Breath of the Wild was the company's last game for the Wii U--and to making sure the Switch's launch problems don't go unaddressed.
As for WHERE and how it updates specifically I'm not sure but I would guess it simply finds the game folder whether on SD-Card or the onboard flash memory and change the appropriate data there.
Switch cartridges are not SD cards.
I would love to see them make another version of the console without the hand held with a bit beefier hardware to display all games at 1080p, I would then buy it without question.
As to the update/cartridge thing, it's possible they put some flash memory on the cartridge for updates...?
Even the PS4/XBone can't put out 1080p/60. 900p/30'ish all day, but that's it. It's tragic. At least the PS4 Pro, SOME games give you the option to choose between 4K/30 and 1080p/60, but seriously. It took this long for consoles to catch up to where PCs have been for over a decade.
I would be fine with 1080p 30fps if that was the minimum fps. And would happily sacrifice the in-game detail settings to achieve this. I don't think there is anyone on this forum that would drop from their monitors native resolution, rather than tweaking detail settings, to get their desired fps.
It really depends on the game for me. 1080p/native resolution is a must, but sometimes I need 60fps, sometimes I could settle for 30. But in either event, it at least has to be a smooth framerate. If it's inconsistent, that's a pretty awful experience. And yeah, I'm totally fine with sacrificing a little eye candy to improve things. From the couch, I'd never notice the difference.