> RAM sticks have a little tag chip that tells a PC "how much RAM this stick has", but RAM chips themselves don't - so the device has to infer its RAM capacity from elsewhere

I'm surprised that in 2026 this is still true.

You could easily fit a little microcontroller on the die of each RAM chip which reports its make/model/manufacturing date, capacity and capabilities, can be triggered to run self-tests, etc. If they aren't doing that yet, I'm surprised that they aren't.

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misnome an hour ago | parent | next [-]

Why bother with the expense if you are permanently soldering it in anyway?

	▲	skissane an hour ago \| parent [-]
		Well, it turns out they actually are bothering – while in DDR thru DDR4, the mode registers are write-only, LPDDR2 onwards have an MRR (Mode Register Read) command, which the CPU/chipset can use to inspect the manufacturer and capacity; and DDR5 has copied the same facility from LPDDR.

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u8080 an hour ago | parent | prev [-]

Upgrading my RAM firmware when