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Recommends/PC parts/PC builder

Build your own PC

What goes where, in what order, and a checker for the six mistakes that actually catch people out.

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Read this bit first

Compatibility checker

Fill in what you are thinking of buying. Everything updates as you type, and each answer explains itself rather than just going red. Leave anything blank that you have not decided yet.

Processor socket

Printed on the processor's product page. AMD and Intel chips never fit each other's boards.

Motherboard socket

Has to be the same as the processor above. This is the single most common ordering mistake.

Memory type you are buying

DDR4 and DDR5 sticks are notched differently and physically will not swap.

Memory the board takes

On the board's specification page. A board supports one or the other, never both.

Motherboard size

A case fits its own size and anything smaller, never anything larger.

Largest board the case takes

Listed on the case as "motherboard support".

Graphics card length mm

On the card's specification page. Modern cards are often over 300mm.

Card clearance in the case mm

Listed as "maximum GPU length". Leave a little room for the power cables.

Cooler height mm

Only for air coolers. Skip this if you are using a liquid cooler.

Cooler clearance in the case mm

Listed as "maximum CPU cooler height". Tall air coolers foul side panels constantly.

Processor power draw W

Look for TDP, or better, the maximum or boost power figure.

Graphics card power draw W

Often called total board power. Leave blank if there is no separate card.

Power supply W

Buy from a brand you have heard of. A cheap one failing can take other parts with it.

Fill in a few boxes above and the checks will appear here.

Putting it together

The order matters more than people expect. Doing the fiddly bits while the board is still out of the case saves a lot of swearing later. Set aside an afternoon rather than an hour, and do not do it on carpet.

  1. Get the board ready on the desk, not in the case

    Put the motherboard on its own box. Fit the processor, the memory and the main drive now, while you can see and reach everything. Once the board is screwed into the case those same jobs are done blind, around cables, at an angle.

  2. The processor drops in, it never pushes

    There is a triangle marked on one corner of the chip and a matching one on the socket. Line those up and it falls into place under its own weight. If you are applying any force at all, stop and look again, because bending pins is the one mistake that is genuinely expensive.

  3. Memory goes in the right pair of slots

    With two sticks the board's manual will tell you which two slots to use, and it is almost never the two nearest the processor. Using the wrong pair halves your memory bandwidth and the machine will not tell you. Press each end down until the clips snap up on their own.

  4. Cooler on, and go easy with the paste

    Most coolers arrive with paste already applied, so check before adding more. If you are applying it yourself, a blob about the size of a grain of rice in the middle is plenty. Tighten the screws a little at a time in a criss cross pattern rather than one at a time.

  5. Now into the case, standoffs first

    Those little brass pillars hold the board off the metal tray. Fit them to match your board's holes before the board goes near the case, and make sure there is not a stray one where there is no hole, because that shorts the board out. Do not forget the input output shield if the board did not come with one attached.

  6. Power supply and cables

    The big 24 pin connector and the separate processor power connector at the top of the board both need to be in, and that top one is the one people miss. Route what you can behind the tray. If the machine does nothing at all when you press the button, this is the first thing to check.

  7. Graphics card last

    It goes into the top slot of that type, and it needs its own power cables from the supply. Fitting it last keeps it out of your way while you are reaching into the case.

  8. Test before you tidy

    Before you spend twenty minutes on cable management, plug in a monitor and keyboard and turn it on. Get into the setup screen, check the memory and the drive both show up, and enable the memory speed profile, because otherwise fast memory runs slow. Only then close it up.

Parts on the table and nerves failing?

No shame in it, the processor step puts people off for good reason. I can build it with you so you understand what is inside it, or take the boxes and hand it back working. Either is fine.

Where to buy the parts