1. Match the CPU, socket and BIOS
The CPU name alone does not prove compatibility. AM4, AM5, LGA1700 and LGA1851 CPUs all need the correct motherboard socket and chipset support. Some boards also need a BIOS update before newer CPUs will boot.
| Platform | What to check |
|---|---|
| AMD AM4 | Ryzen 5000 support often depends on BIOS version, especially on older B350, X370, B450 and X470 boards. |
| AMD AM5 | Check DDR5 memory cost, board BIOS support and whether the CPU has integrated graphics. |
| Intel LGA1700 | Confirm DDR4 or DDR5 board type and generation support for 12th, 13th and 14th Gen CPUs. |
| Intel LGA1851 | Check motherboard price and upgrade path before choosing it over AM5 or LGA1700. |
2. Inspect the CPU physically
PinsAM4 pins bend easily
Ask for bright close-up photos of all corners and rows before buying an AM4 CPU.
PadsLGA CPUs use contact pads
For AM5 and Intel CPUs, look for scratched, stained or missing contact pads.
HeatCheck overclocking history
High-end unlocked Intel CPUs and X3D CPUs should have proof of stable operation and sensible cooling.
3. Compare the whole platform cost
A cheap CPU can become expensive if it needs a new motherboard, RAM, cooler or BIOS flash service. Compare CPU price together with platform cost, not as a standalone part.
- For AM4 upgrades, check whether a 5700X3D or 5800X3D extends an existing system cheaply.
- For AM5, include DDR5 and motherboard price in the comparison.
- For Intel, confirm whether the board is DDR4 or DDR5 before buying memory or CPU.