https://www.videogameschronicle.com/news/sources-nintendo-showed-switch-2-demos-at-gamescom/

Basically both VGC and Eurogamer are stating today that their sources are telling them Switch 2 was indeed shown at Eurocom a few weeks ago behind closed doors to devs. So what was shown? Apparently a Zelda: BOTW enhanced version and ... according to VGC, The Matrix Awakens Unreal Engine 5 demo was shown running on Switch 2. 

The demo is pretty much the high end from what I've seen of next-gen graphics. VGC states the demo was utilizing Nvidia's DLSS technology. Here is the demo on PS5/XBSX for those who haven't seen it:

Per VGC article:

https://www.videogameschronicle.com/news/sources-nintendo-showed-switch-2-demos-at-gamescom/

One ‘Switch 2’ demo is understood to have been an improved version of the Switch launch title Zelda: Breath of the Wild, running at a higher framerate and resolution than the original game did, on hardware targeting the new console’s specs (but there was no suggestion the game will actually be re-released.)

The demo is said to have been running using Nvidia’s DLSS upscaling technology, with advanced ray tracing enabled and visuals comparable to Sony‘s and Microsoft’s current-gen consoles (however, it should be noted this does not mean the Switch successor will sport raw power anywhere near that of PS5 or Xbox Series X, which aren’t portable devices).

DLSS is going to be a massive game changer for the Switch 2 if the article is legit

Correct me if I'm wrong, but doesn't DLSS look terrible when used on a 30fps game?

I've never heard that, are you thinking of FSR or something else? 

This rumor makes it seem like DLSS will essentially be able to entirely close the gap between handheld performance and console performance. I am definitely suspicious of such a large claim. Though I do think DLSS may significantly close the gap, perhaps allowing next gen Nintendo ports of PS5/XBSeries games with performance set to lower settings, ray tracing turned off (despite this rumor claiming next gen Nintendo has ray tracing, I very much doubt that as it would be a huge waste of resources for a handheld), and minimal other changes needed. The idea, as this rumor suggests, that it will be on par with console graphics in every way, seems far fetched.

I understand DLSS 2.0 to be able to do about a 2x-3x performance enhancement. I would think that, along with running games at below 4k (after DLSS) plus 30fps for most games instead of 60fps and turning off ray tracing would probably be enough, as i said, to allow console games to play on Nintendo's handheld with no or very minimal graphical downgrades. If Switch 2 can even do this, rather than the much more significant claims of this rumor, that would be HUGE as it would mean AAA high-end graphics console games could get ported to Nintendo without much work done, just turn some settings down, turn on DLSS, and do the normal port tweaking you have to do as with any port between systems.

Why would the fps matter?

That wouldn't seem to make any sort of logical sense. DLSS is an incredibly efficient upscaling technology, allowing games to run at much lower resolutions and then be greatly upscaled with little resources used. Wouldn't matter what the framerate is.

I have a suspicion that DLSS can do more than what Nvidia pushes it as because they don't want people being able to run games uses like lower power GPUs, that wouldn't be great for their sales, so they kinda really only emphasize and advertise it in areas like 8K upscaling.

They don't really push the whole "run a game at 360p and upscale it to 1080p!" aspect. 

But for a device like Switch 2 ... I could totally see Nintendo basically hardwiring features like that right into the dev kit and dev pipeline. Nvidia shouldn't really care because Switch 2 is not really a threat to their GPU business, so if the dev kits for the Switch 2 are more fine tuned to utilize DLSS at super low native resolutions it's not really a big deal for Nvidia. 

Also DLSS 3.5 *does* work on all RTX cards, it's just the frame reconstruction feature is only for 40 series cards, but the better image upscaling that 3.5 might provide + the ray-tracing reconstruction aspects of DLSS 3.5 will work on any card with RTX cores according to Nvidia directly. That means these features should function on the Switch 2. Who even knows maybe the frame generation feature even works. The guy who leaked the Tegra T239 chip I believe said while the Switch 2 is Ampere-based it may have some Lovelace (30 series) features too (IIRC) ... that's Nvidia 30 series cards, 30 series can do the frame generation trick. 

I tried to look it up now and all the videos are specifically about DLSS 3 so maybe it's only a problem with that version of it? I don't really know:

https://youtu.be/PUTsE1q1bYI?si=IBmbuzeaNLE6rGNV&t=275

I think what you are talking about is the frame generation feature of DLSS 3.0+ (go to 4:35 in the video):

This is frame generation, not sure the Switch 2 will feature this at all. 

It can be a little confusing because DLSS is basically now 3 different things according to Nvidia

1.) The upscaling feature (taking an image of low resolution and making it appear far higher resolution)

2.) The frame generation feature was introduced in DLSS 3.0, this only works on 40 series card.

3.) Ray tracing reconstruction allows for denoising and better quality ray tracing without a performance hit. 

1 and 3 should work on the Switch 2 as they work on all RTX cards. 2 though is exclusive to 30/40 series GPUs, so that may not apply to the Switch 2 at all. 

DLSS so far has 3 main features that developers can choose to implement

DLSS Super Resolution
DLSS Frame Generation (Exclusive to RTX 40 series and newer)
DLSS Ray Reconstruction

With DLSS Frame Generation (some people call it DLSS 3 as that is when that feature was introduced) generally works better with higher base frame rate. The article however is mentioning DLSS Super Resolution so it's a different feature that doesn't rely on a high base frame rate.