Soldered RAM capacity is locked at the factory.

The CPU sets the theoretical maximum—how many gigabytes per channel the memory controller can address. But the board design and the specific chips the manufacturer soldered on that motherboard determine what you actually get. And you can’t change it.

Laptops with soldered RAM have a fixed capacity because the memory is physically attached to the board. The CPU might support 64GB or 128GB, but if the manufacturer soldered 8GB chips in a two-channel configuration, you get 16GB. Period. Sometimes they leave an empty slot for expansion, but if it’s fully soldered, that’s your ceiling.

So the limit is both: the CPU’s memory controller defines the absolute max, but the board design (how many chips, what density, and whether there are expansion slots) decides the hard limit for that specific machine.

Check the specs before you buy. Future you can’t just “add more RAM.”