Work out what RAM your desktop can take
Find the generation, speed, capacity limit and free slots before you buy a single stick.
Safety level: safe diy · Time: about 15 minutes · Level: beginner
Applies to
- Desktop PCs
- Not laptops - see the laptop RAM guide
You will need
- Nothing - this is all done in software
Find out exactly what memory your desktop accepts, before buying anything. This is all done in software; nothing needs opening.
Applies to
Desktop PCs running Windows 10 or 11. Laptops have different rules — many have memory soldered to the board — and are covered in the laptop RAM guide.
Before you start
Nothing to prepare. No part of this touches hardware.
Steps
- Open Task Manager (Ctrl+Shift+Esc) and go to Performance → Memory. Note four things: the total installed, the Speed, the Slots used (for example "2 of 4"), and the Form factor — DIMM for a desktop.
- Find the generation. Task Manager reports speed but not always the generation clearly. DDR4 typically reports 2133–3600 MT/s; DDR5 typically 4800 and above. If it is ambiguous, the motherboard model is definitive.
- Identify the motherboard. Press Windows+R, type
msinfo32, and read BaseBoard Manufacturer and BaseBoard Product. Write both down exactly.
- Look up that exact board on the manufacturer's site. Its specification page states the memory type it accepts, the maximum total capacity, the number of slots, and the speeds it supports. This page is the authority — not a general article, not a shop listing.
- Check the free slots. "2 of 4 used" means you can add without removing anything. "2 of 2" means an upgrade replaces what is there, so budget for a full kit rather than extra sticks.
Expected result
You can state: the generation (DDR4 or DDR5), the maximum total the board takes, how many slots are free, and the speed the board actually runs.
If it does not work
- Task Manager shows no Slots used — some prebuilt machines hide it. Use the motherboard specification instead, or ask us with the board model.
- The board is from a prebuilt (Dell, HP, Lenovo) — look up the machine's service tag on the maker's support site rather than the board, which often has no public page.
- Speed reported lower than the sticks are rated — normal. Memory runs at a default speed until the XMP or EXPO profile is enabled in the BIOS.
Buying it
Match the generation, buy a matched kit rather than mixing, and do not pay for a speed above what the board supports — it will simply run slower.
Mixing existing sticks with new ones of a different brand or speed sometimes works and sometimes will not boot. If the machine is important to you, replace the set.
Stop and ask a technician if
The machine is under a manufacturer warranty you do not want to affect, or the board is in a prebuilt with a proprietary layout. Bring us the model and we will tell you what it takes.
Read this next
- DDR4 or DDR5: which do you need, and does it matter? — Once you know which generation your board takes, this is what actually changes between them.
- Fit desktop RAM safely — The fitting steps, once you have the right module in your hand.
- New memory is not detected, or the PC will not boot after fitting it — If the module is in and the machine still will not see it.
Still stuck?
If anything here does not match what you are seeing, stop rather than force it. Contact us · Book a repair
Last reviewed 2026-08-19.