Windows 10 fixed this sometime around the end of 2020, where you have igpu and a discrete - prior to whatever patch they pushed, if you alt tabbed out of a fullscreen game, there was a good chance that the game window would be a 1" square when you alt tabbed back, if it didn't crash in the meantime.
The "black screen for a couple seconds" thing is still there, you just don't notice it, and once a game has "started" the discrete GPU, you can seamlessly switch back and forth.
some people are mentioning that "i can't believe it took 10 years for this to get fixed" - however back in the late 90s this exact scenario was the most common power gaming setup, with 3dfx cards you'd have 3 cards, two 3d cards with SLI, and a 2D card, usually an intel. The same black screen for a couple seconds, and switching between the desktop and a game had the potential to break things.
The "automatic" switching between igpu and discrete was managed on windows before 2011, because i had a laptop with that setup in 2011 and it would detect 3d applications and use the discrete for that, or you could force one gpu or the other, if you wanted.
The "black screen for a couple seconds" thing is still there, you just don't notice it, and once a game has "started" the discrete GPU, you can seamlessly switch back and forth.
some people are mentioning that "i can't believe it took 10 years for this to get fixed" - however back in the late 90s this exact scenario was the most common power gaming setup, with 3dfx cards you'd have 3 cards, two 3d cards with SLI, and a 2D card, usually an intel. The same black screen for a couple seconds, and switching between the desktop and a game had the potential to break things.
The "automatic" switching between igpu and discrete was managed on windows before 2011, because i had a laptop with that setup in 2011 and it would detect 3d applications and use the discrete for that, or you could force one gpu or the other, if you wanted.