Soldered RAM locks you into its speed.

Yes. You cannot swap soldered RAM for faster modules. It is physically attached to the motherboard—no slots, no upgrades, no swapping.

If your laptop or mini PC came with DDR5-4800, you are stuck at DDR5-4800. The controller and firmware might support higher speeds, but the chips are what they are. You get what you bought, period.

This is the trade-off for thinness and battery life in modern ultrabooks and Macs. If you think you might want faster memory later, buy the higher-speed configuration upfront, or get a machine with slot-based RAM.

Choose your spec wisely. There is no do-over.