1. Processor and motherboard
The first step is checking the socket. AMD Ryzen AM4 processors do not fit AM5 motherboards; Intel LGA1700 CPUs do not fit LGA1851 boards. Even when a socket looks similar, the chipset and BIOS can limit compatibility.
2. Generation, chipset and BIOS
A motherboard can have the correct socket and still need a BIOS update. Check the manufacturer's list of supported processors and confirm that the installed version is compatible. The chipset also defines features such as overclocking, number of ports, PCIe lanes and connectivity.
When buying a board for a new processor, prefer models with BIOS Flashback or CPU-less updating where available. That lowers the risk of the board not starting on the first build.
3. RAM: DDR4 and DDR5 do not mix
DDR4 and DDR5 have different physical notches and cannot be swapped. It is not enough for the memory to have the same capacity or advertised frequency: the motherboard must declare support for the right standard.
- Confirm whether the board uses DDR4 or DDR5.
- Check the maximum capacity and number of slots.
- Check the QVL list if you plan to use high-frequency kits.
- Install modules in the pairs recommended by the manual to benefit from dual-channel.
4. Graphics card, case and motherboard
The GPU normally uses a PCIe x16 slot. Different PCIe generations are generally backward compatible, but the card will run at the speed limited by the oldest component. The most common problem is not the slot: it is the card not fitting in the case or blocking other slots.
Measure length, height and thickness. A three-slot card can prevent installing an expansion card or sit too close to the power supply. Also check whether the case supports radiators and whether there is enough air intake.
5. Power supply and connectors
The power supply must deliver enough power and have the right connectors. Add up the approximate consumption of CPU and GPU, allow headroom for peaks and do not choose by the watt number printed on the box alone.
- Entry-level GPU: many use only slot power or a 6/8-pin connector.
- Stronger GPU: may require several 8-pin connectors or 12VHPWR.
- CPU: confirm the motherboard's 4+4 or 8-pin EPS connector.
- Avoid low-quality adapters and power supplies without reliable protections.
6. Cooler and socket
The cooler must include the mounting kit for the chosen socket. A heatsink compatible with AM4 may need a different bracket for AM5 or Intel. Also check the air cooler's maximum height and the radiator size if you choose a liquid cooler.
Memory clearance matters: wide towers can cover the first DIMM slot. With liquid coolers, check position, hose length and the case's support for 120, 240 or 280 mm radiators.
7. Storage and expansion
Check how many M.2 slots the motherboard has, which use PCIe 3.0, 4.0 or 5.0 and whether any is disabled when certain SATA ports are used. A PCIe 4.0 SSD works in a 3.0 slot, but at a speed limited by the board.
Checklist before buying
- CPU socket and generation match the motherboard.
- BIOS supports the chosen processor.
- DDR4 and DDR5 are correctly identified.
- GPU fits the case and has enough power.
- Cooler is compatible and fits without blocking the RAM.
- Power supply has suitable wattage, quality and connectors.
- SSD and add-in cards do not compete for the same PCIe resources.