For a new build that you expect to upgrade later, buy AM5. It is AMD's current socket, it takes the newest Ryzen processors and AMD has said it will be supported through 2027 and beyond. AM4 is the better buy in two cases: you already own an AM4 system and want a cheap, worthwhile upgrade, or your budget is tight enough that reusing or buying DDR4 memory and an older Ryzen chip makes the difference.
The two platforms side by side
| AM5 | AM4 | |
|---|---|---|
| Launched | 2022 | First Ryzen processors in 2017 |
| Socket type | LGA1718: the pins are in the motherboard socket | PGA: the pins are on the processor |
| Processors | Ryzen 7000, 8000G and 9000 | Ryzen 1000 to 5000, depending on chipset and BIOS |
| Memory | DDR5 only | DDR4 only |
| Fastest PCIe | PCIe 5.0, for graphics and M.2 depending on chipset and board | PCIe 4.0 on X570 and B550 with a suitable CPU; PCIe 3.0 on older and entry-level chipsets |
| Chipsets | X870E, X870, B850, B840, X670E, X670, B650E, B650, A620 | X570, B550, A520, B450 and older |
| Future CPUs | AMD has said AM5 is supported through 2027 and beyond | None expected; the platform is complete |
Why AM5 is the default for a new build
The main argument is time. An AM5 board bought now takes three families of processor already, and AMD's stated support runs beyond 2027. AM4 showed what that is worth: people who bought a sensible board early in its life were able to drop in a much faster processor years later without touching anything else. There is no guarantee that AM5 will run as long, but AMD's public commitment is the best indication available on any current desktop socket.
The second argument is the processors themselves. The fastest Ryzen chips for gaming and for heavy work are AM5 only. If you want current-generation performance, the decision is made for you.
Third, AM5 brings PCIe 5.0. How much you get depends on the chipset: X870E, X870, X670E and B650E guarantee it for the graphics slot and an M.2 slot; B850 guarantees it for M.2; on B650 it is optional and board dependent. Few people need it today, as our PCIe 5.0 guide explains, but it costs little on a mid-range board.
What AM5 costs you
AM5 is DDR5 only. You cannot carry DDR4 over from an older PC, and no AM5 board has DDR4 slots. Boards also start at a higher price than the cheapest AM4 boards, although A620 and basic B650 models have narrowed the gap considerably. A620 and B840 do not allow CPU overclocking, and B840 runs its chipset lanes at PCIe 3.0, so for a build you intend to keep, B650 or B850 is the more comfortable floor.
The socket design changed too. AM5 puts the pins in the board, as Intel has done for years. That makes the processor harder to damage and the socket easier to damage, which matters if you are considering an open-box board. Inspect the socket before fitting anything; our used motherboard checklist shows how.
When AM4 still makes sense
- You already have an AM4 PC. Moving from an early Ryzen chip to a Ryzen 5000 processor is one of the cheapest large upgrades in PC building. You keep the board, memory and cooler. Check the board's CPU support list and update the BIOS before swapping, as support depends on chipset and BIOS version.
- Your AM4 board has failed. A replacement B550 or B450 board keeps a working processor and memory in service for far less than a new platform.
- The budget is fixed and low. An AM4 board, a Ryzen 5000 processor and DDR4 can undercut the AM5 equivalent, and the result is still a capable PC for 1080p and 1440p gaming and everyday work.
If you do buy into AM4 new, B550 is the sensible choice: PCIe 4.0 for the graphics card and the main M.2 slot, and support for Ryzen 3000 and 5000 processors. X570 adds PCIe 4.0 from the chipset as well. A520 is PCIe 3.0 only and does not overclock the CPU, and B450 is PCIe 3.0 and may need a BIOS update before a Ryzen 5000 chip will start. Go in knowing that the board will never take a newer processor than the 5000 series.
Warehouse boards on either platform
AM4 boards have been on sale for years, so they turn up regularly among Amazon Warehouse offers, and a replacement or upgrade board is exactly where an open-box saving is attractive. On AM4 the pins are on the processor, so the usual open-box worry about bent socket pins does not apply to the board in the same way.
On AM5 the BIOS is the thing to check. A B650 or X670 board made before Ryzen 9000 was released may need a BIOS update before it will start with a 9000-series chip. Most AM5 boards have a CPU-free update button, but not all. See BIOS updates and CPU compatibility and are Amazon Warehouse motherboards worth it.
Verdict by type of buyer
- New gaming or general PC, planning to upgrade later: AM5, on a B650 or B850 board. See B850 vs B650.
- New PC on the lowest possible budget: AM4 with B550 is still defensible, but price an A620 or basic B650 build first. The gap may be smaller than you expect.
- Existing AM4 owner wanting more speed: stay on AM4 and change the processor. It is the best value on either platform.
- Existing AM4 owner with a dead board: replace it with a B550 or B450 board, new or Warehouse.
- Heavy workloads, top-end graphics card or lots of fast storage: AM5, and read X870E vs X870 vs B850.
Not sure AMD is the right side of the fence at all? AMD vs Intel motherboards compares the platforms.
Questions people ask
Can I use an AM4 processor in an AM5 motherboard?
No. The sockets are physically different: AM4 processors have pins and AM5 processors have flat contacts. Nothing is interchangeable between them except, in many cases, the cooler.
Can I reuse my DDR4 memory on AM5?
No. AM5 is DDR5 only, and no AM5 board has DDR4 slots. DDR4 and DDR5 modules are keyed differently and will not fit each other’s slots.
Will my AM4 cooler fit an AM5 board?
Often, yes. AMD kept the same mounting hole spacing, and coolers that attach to the standard backplate generally fit. Coolers that use their own replacement backplate may not, because the AM5 backplate is fixed to the board. Check the cooler maker’s compatibility list.
Is AM4 dead?
It is complete rather than dead. No new processor generations are expected, but Ryzen 5000 chips remain capable and the boards are inexpensive. It is a sound choice for upgrades and repairs, and a reasonable one for a strict budget build.
How long will AM5 be supported?
AMD has said AM5 is supported through 2027 and beyond. That is a statement of intent and not a list of products, and we are not aware of an equivalent public commitment for any other current desktop socket.