Why is my ram capacity more in wmic memphysical get maxcapacity in cmd?

Solution 1:

wmic memphysical get maxcapacity

Does not take into account motherboard layout, wiring and limitations unless the motherboard manufacturer has been very careful to set things up in the firmware. It is a command best used on desktops where all memory channel and slots are available.

By default that number will simply report what the CPU tells it is the maximum capacity. Most CPUs have two channels for memory, and assume that each memory channel will support 2 memory sticks.

Laptops though often lack the second memory stick which would essentially halve the amount of memory you can fit. That would take your value of 67108864 KB (64G) down to 32GB.

Some cheap laptops will also only have one memory stick wired up full stop. That would limit you to 1/4 of the CPU total capacity. As the CPU can (fully populated) handle 64GB then using only 1 stick on 1 memory channel will mean it is limited to a single 16GB DIMM.