Will these PC parts fit together? A compatibility checklist

Building or upgrading a PC is mostly a matter of making sure each part fits the next. Nothing here is difficult, but one wrong part can stall a whole build. Work through the checks in order, then use the list at the end before you order.

Processor and motherboard: the socket

The processor must match the socket on the motherboard. This is the one check that cannot be worked around.

Socket	Processors	Memory
AMD AM4	Ryzen 1000 to 5000 series	DDR4
AMD AM5	Ryzen 7000, 8000 and 9000 series	DDR5
Intel LGA 1700	12th, 13th and 14th generation Core	DDR4 or DDR5, depending on the board
Intel LGA 1851	Core Ultra 200 series desktop	DDR5

Memory: DDR4 or DDR5

A motherboard takes DDR4 or DDR5, never both. The two do not fit each other's slots.

• Desktops use full-size modules (DIMM). Laptop memory (SODIMM) does not fit.
• Buy memory as a matched kit of two modules for best performance.
• Check the maximum speed and capacity the motherboard supports.

Case and motherboard: the size

Motherboards come in standard sizes, and the case must support the one you choose. From smallest to largest: Mini-ITX, micro-ATX, ATX and E-ATX. A larger case usually takes smaller boards, but not the other way round.

Graphics card: length and power

• Length and thickness. Compare the card's dimensions with the maximum graphics card length in the case specifications.
• Power connectors. Check which connectors the card needs and that your power supply has them. Newer high-end cards use a 12V-2x6 connector.
• Recommended power supply. Each card lists a minimum wattage.

Cooler: socket, height and radiator

• The cooler must list your processor socket.
• For an air cooler, compare its height with the case's maximum cooler height.
• For a liquid cooler, check that the case has a mounting position for the radiator size: 240mm, 280mm or 360mm.
• Many processors are sold without a cooler. Check the listing.

Power supply: wattage and size

Add up the power your parts need and leave headroom. The graphics card's recommended wattage is the simplest guide. Most cases take a standard ATX power supply, while small cases may need the shorter SFX size.

Storage: slots and types

• Check how many M.2 slots the motherboard has, and whether they support NVMe.
• 2.5-inch SSDs and hard drives need a SATA port on the board and a drive bay in the case.

The checklist

Tick each one off before you order.

• The processor and motherboard use the same socket
• The motherboard's BIOS supports my processor, or can be updated
• The memory is the right type for the board: DDR4 or DDR5
• The memory is desktop size (DIMM), not laptop size
• The case supports my motherboard size
• The graphics card fits the case's maximum length
• My processor has built-in graphics, or I am buying a graphics card
• The cooler supports my socket and fits the case
• The power supply has enough wattage and the right connectors
• The motherboard has the storage slots I need
• I have an operating system, or have included one

Find the parts in the store: processors, motherboards, memory, graphics cards, cases, cooling, power supplies and storage.

Frequently asked questions

How do I know if a processor fits my motherboard?

Check that both use the same socket, such as AM5 or LGA 1700. Then confirm on the motherboard maker's support page that the board's BIOS supports that processor.

Can I use DDR4 memory in a DDR5 motherboard?

No. DDR4 and DDR5 use different slots and are not interchangeable.

How do I know if a graphics card will fit my case?

Compare the card's length in its specifications with the maximum graphics card length listed for the case. Also check the thickness if other cards sit below it.

What size power supply do I need?

Use the recommended wattage listed for your graphics card as a starting point, and choose a unit with the power connectors that card needs.

Do I need a graphics card if my processor has built-in graphics?

Not for office work, browsing and video. For modern games and 3D work you need a dedicated graphics card.