How much better does Unity Games run on Laptops VS UE4?

As the title says

how much easier is the average Unity game to run on onboard GPU these days AMD APU etc compared to UE4 indie titles

 

It's entirely dependent on the work the dev puts into it. UE4 can be scaled down but it won't scale down as much as Unity.

 

This is what I understand, I wonder though is it significant enough these days with modern laptops to pick Unity over UE4 for the purpose of performance on integrated GPU?

 

It entirely depends on the game. But as far as starting from an empty project, UE4 enables several post processing graphics effects by default which all impact performance, while Unity doesn't have any until you set up the post processing stack yourself or add 3rd party effects. So a very basic game will technically perform better made with Unity on low end hardware..... Not really a big deal since you can just go and disable all the effects in UE4.

 

If your target market is casual players who don't obsess about gaming hardware, you'll probably have better results with Unity. Anything without dedicated VRAM is likely to have really awful performance with 3D either way though, even with many features turned way down.

But I have seen exceptions - Dungeon Defenders (UE3-based) runs perfectly on its lowest graphical setting (only three settings to choose from) on a 4th generation Intel with HD4000 integrated graphics. UE4 games seem to aim higher as a minimum.

There's also editor performance, in case you're thinking of working on a laptop. UE's editor is again more demanding than Unity's. With HD40000/Iris/Iris Pro integrated graphics Unity is fine to work with for 2D. UE4 was a pain on anything short of a dedicated gaming GPU (even low-end) last time I tried it.

Workflow also matters, so you might like one engine over another because of how easy something is to do in the process of building your game. Then you might care less about the audience

 

I would imagine either engine can be very light. It would depend on assets/shaders/etc. Both engines have been running on mobile for some time, and developers have managed to create a lot of great performing games.