SO-DIMM vs. Soldered RAM
Last reviewed 8/18/2026
SO-DIMM (Small Outline Dual In-line Memory Module) is a removable memory stick that slots into a laptop's motherboard. Soldered memory is fixed permanently to the board at manufacturing time. The choice affects upgradeability, repairability, and — to a lesser extent — how thin a laptop can be built.
SO-DIMM
A physical module, similar in concept to desktop DIMMs but smaller, that clicks into a slot and can be removed or replaced without special tools beyond a screwdriver to access the compartment. This is what makes a RAM upgrade possible after purchase.
Soldered (onboard) memory
Memory chips attached directly to the motherboard during manufacturing. This allows thinner designs and can slightly improve power efficiency and signal integrity, but means the installed capacity is permanent — there is no user upgrade path, and a memory failure typically means replacing the whole board.
CAMM2 — a newer alternative
Some newer laptop platforms use CAMM2 (Compression Attached Memory Module), a flatter, single-module alternative to a pair of SO-DIMMs. It's still a removable, user-serviceable module in laptops that support it — it isn't the same thing as soldered memory, even though it looks less like a traditional stick.
Why manufacturers choose one over the other
Ultra-thin and fanless designs often favor soldered memory to save the vertical space a SO-DIMM slot requires. Business and workstation-class laptops more often keep SO-DIMM slots (sometimes alongside some soldered baseline) specifically to support IT department upgrades and repairs over the device's service life.