What is an "emulation ceiling"?

A device’s emulation ceiling is the most demanding console generation it runs acceptably. Below the ceiling everything is smooth; at it, titles are playable with some tuning; above it, they struggle or fail. Ceilings rise by chipset tier — PS1/SNES for entry chips, PSP/DS/N64 in the middle, PS2/GameCube/Wii higher, 3DS/Wii U/Switch only near the top. We report ceilings as consensus bands from published testing because the hardest titles on a system sit below the easy ones, and individual games vary. Our Emulation Ceiling Finder turns the tiers into a table you can shop against.