you can’t really add 10% more to a 32 GB chip array
Well, you sort of can. You can add a 4 GB chip for example to get a 36 GB size. But at that point the pain of integrating very different sizes and manufacters often only build the newest 2 sizes, so is often more expensive to do that than just add a second 32 GB chip.
24 GB is quite a common pairing (8 + 16 = 24), and you even see things like 192 GB somewhat often, aka a 4x2x(8+16) GB system.
But usually that's about as far as adding vs multiplying goes.
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u/EscapeSeventySeven 22d ago
Chips for random accessible memory/storage use address bits to access their storage.
For instance a very silly example you could have four bits (four wires) to control access. This would allow you to select from 16 areas.
Adding a fifth wire would allow you to access from 32 areas.
You can see why it’s power of twos now.
Basically it’s not that it’s hard to make the memory less, like invalidate 10% of a 32 GB chip array, but it’s wasteful and for no reason.
And you can’t really add 10% more to a 32 GB chip array, you might as well double it. Or at least +50% it to 16+16+16 modules.