Soldered RAM doesn't save you any real power.

Not really. The power difference between soldered and socketed RAM is tiny — like negligible, can’t-measure-it-without-a-lab-micrometer tiny.

The actual memory chips are the same. Soldering them to the motherboard just removes a connector and shortens the trace length. That might lower resistance by something like 0.01 watts under load, if that. You won’t see it in battery life or heat output.

Manufacturers solder RAM to save space, make thinner laptops, and — let’s be honest — prevent you from upgrading later. Power savings are a convenient marketing bullet point, not a real-world advantage.

If you’re choosing between a soldered and socketed laptop, don’t let power consumption be the deciding factor. Upgradeability matters way more.