Soldered RAM's power savings are mostly theoretical.

Negligibly. You won’t notice the difference.

The physics argument for soldered RAM saving power is real but tiny. The memory chips themselves draw the same current whether soldered or on a stick. The difference comes from the extra traces and connector resistance in socketed modules. In practice, that’s on the order of 0.1–0.5 watts per stick — a rounding error next to the CPU or display.

The bigger power variable is total capacity and speed. More RAM draws more power regardless of how it’s attached. Faster sticks (DDR5 vs DDR4) also consume more. If you’re worried about battery life, optimizing those numbers matters way more than soldered vs. socketed.

The real tradeoff is repairability and upgrade cost, not power. Soldered RAM keeps laptops thin but makes them disposable. Socketed RAM wastes a negligible amount of electricity but saves you from buying a whole new laptop when 8GB stops being enough.

Don’t let power consumption drive your RAM decision. Future you will thank you for having an upgrade path.