That's not how merging works! ;) <3

Magic!

Voodoo... the world now has two less chickens and a bottle of rum has been drunk

@DevilLady Think of it as a DJ playing/mixing two songs at once - at times toning down the loudness of one song to let the other shine through, at times playing both together - creating a new song that incorporates elements of both, while retaining the same length (or in our case: filesize).

Because all checkpoints contain the same amount data. It's an extremely large slider panel, if you will.

It doesn't contain any images, but information on how various things look, in form of numeric values, aka sliders.

When you merge 3 models, you don't make the slider panel 3 times larger, but instead you set the slider positions to the average between those 3 models.

@UndefinedUsername I suppose I should know this, but I don't.... How do we end up with SOME checkpoints that are like 5gb? I've seen one popular one out there at 8gb if "all checkpoints contain the same amount of data"... I tend to believe you are correct, as there are only so many ways to define "fish" unless the HUGE ckpt tell the system, "Well... most 'fish' look like THIS, buuuut, there's tuna, marlin, sturgeon, sunfish, etc."

@Inland389 I had same questions once I started. The simplest answer would be probably something like this. Bigger files usually mean they are non pruned versions. What this means is that they contain some extra data which is helpful when one wants to train the model further. Pruned version are striped of some of this data to be smaller, it has almost no impact on what the generations look like. Which is great if you hoard millions of different models on your PC like most of us do lol. 100 models at 2 GB will take a lot less space on your drive compared to having 100 models at 10 GB. If you are just a happy little generator and have no desire to train a model you shouldn't bother too much with it. If you plan to train a model, you would want to keep the other file. Somebody could probably be more technical about it but trust me, if you just started learning about it, its probably best to take it one bite at a time haha, there are some crazy guides / articles on how it all works, but it will probably blow a regular users brain.

@C3RBERUS Yeah... that's the 'just right' amount of info for my current knowledge level of "happy little generator". :) Every so often I get an itch and figure out a new aspect (I'm working on the basics of ControlNet and end up drooling when reading THOSE tutorials)... I think I'm a LONG way from trying to build my own Checkpoint from scratch (not just a "oh, I like this one, and this one and this one! Let's mix 'em" kind of thing). But, I do hope that I will get to that point before this all goes Betamax and the next text-to-image beast comes rolling along.