What RAM do I have?
To sell memory you need four facts: the generation (DDR3, DDR4 or DDR5), whether it’s a desktop, laptop or server module, the capacity, and for server memory the speed. Your computer will tell you most of them, and the sticker on the stick tells you all of them.
On Windows
- Task Manager → Performance → Memory. Shows the total, the speed, how many slots are used, and the form factor — DIMM for a desktop, SODIMM for a laptop.
- CPU-Z, free: the Memory tab gives the type (DDR4, DDR5), and the SPD tab shows each stick’s size, maker, part number and label code.
- PowerShell:
Get-CimInstance Win32_PhysicalMemory | Select Manufacturer, PartNumber, Capacity, Speedlists every stick.
On macOS and Linux
On a Mac, About This Mac shows the memory type and size; only older Intel Macs with slots have memory you can take out. On Linux, sudo dmidecode --type memory lists each stick with its size, type, speed and part number.
Reading the label
A typical sticker reads something like “16GB 2Rx8 PC4-3200AA-UB2”:
- 16GB — the capacity of that stick.
- 2Rx8 — two ranks of x8 chips. It doesn’t change the offer.
- PC4 — the generation: PC3 is DDR3, PC4 is DDR4, PC5 is DDR5.
- 3200 — the speed. Older labels give bandwidth instead: PC4-25600 is DDR4-3200, PC5-44800 is DDR5-5600.
- U, S or R after the dash — unbuffered desktop, SODIMM laptop, or registered server memory.
Retail kits also carry the maker’s part number, and server modules a Samsung, SK hynix or Micron part number — all of which the finder below reads. For DDR4 versus DDR5 by eye, see how to tell them apart.
Look it up
Then see what sets its value or browse the RAM price list.