B550 is the mainstream chipset of the last AM4 generation. It launched in 2020, gives the graphics slot and the main M.2 slot PCIe 4.0, allows CPU overclocking, and is the natural home for a Ryzen 5000 processor. It is also picky about older chips: Ryzen 1000 and Ryzen 2000 are not supported. AM4 was replaced by AM5 in 2022, so treat B550 as an upgrade or replacement platform, not a starting point. Current prices are on the B550 deals page.
Cheapest B550 boards right now
All 96 B550 motherboards, with price drops and price history
Amazon Warehouse offers on B550 boards
Where B550 sits
The final AM4 chipsets are X570 from 2019, then B550 and A520 from 2020. B550 replaced B450 as the mainstream choice. Its main advance was PCIe 4.0 from the processor, which B450 boards do not offer even with a processor that supports it.
Key specifications
| Feature | X570 | B550 | A520 |
|---|---|---|---|
| Launched | 2019 | 2020 | 2020 |
| CPU overclocking | Yes | Yes | No |
| Graphics slot and main M.2 (from the CPU) | PCIe 4.0 | PCIe 4.0 | PCIe 3.0 |
| Chipset lanes | PCIe 4.0 | PCIe 3.0 | PCIe 3.0 |
| Ryzen 2000 support | Yes | No | No |
| Chipset fan | Most boards | No | No |
On B550 the PCIe 4.0 lanes belong to the processor: sixteen for the graphics slot and four for the main M.2 slot. Everything connected through the chipset, which on most boards includes the second M.2 slot, runs at PCIe 3.0 at most. How the remaining slots are wired, and which ports share lanes, varies by board.
Compatible CPUs
This is the part of B550 that catches people out, so it is worth being exact.
- Supported: Ryzen 3000 processors without integrated graphics (such as the Ryzen 5 3600), all Ryzen 5000 desktop processors, and the newer G-series chips with integrated graphics (Ryzen 4000G and 5000G).
- Not supported: Ryzen 1000, Ryzen 2000, and the older G-series parts such as the Ryzen 3 3200G and Ryzen 5 3400G. Despite the 3000 in the name, those two belong to the earlier generation.
If you own one of the unsupported chips and need a replacement board, look at B450, which was built for those generations, or at X570, which supports Ryzen 2000 but not Ryzen 1000. If you are in any doubt, check the board's CPU support list on the maker's website before ordering.
Ryzen 5000 arrived a few months after B550. Boards made in 2020 shipped with a BIOS that predates those processors and need an update before one will start. Most stock sold since then is new enough, but old stock and returns cannot be guaranteed. A BIOS flashback button removes the worry. See BIOS updates and CPU compatibility.
PCIe 4.0 needs a processor that supports it. Ryzen 3000 and 5000 chips without integrated graphics do. The G-series processors are PCIe 3.0 parts, so with one fitted the whole board runs at PCIe 3.0.
Memory
B550 uses DDR4 only. Memory overclocking and XMP profiles are supported, though on AM4 some makers label the setting DOCP or A-XMP. Ryzen 3000 and 5000 processors generally do best with DDR4 at 3200 to 3600 MT/s. Boards have either four slots or, on some small and budget models, two.
B550 against X570 and A520
X570 has PCIe 4.0 on the chipset lanes too, so a second M.2 slot can run at full PCIe 4.0 speed, and it supports Ryzen 2000. Most X570 boards have a small chipset fan; B550 boards do not need one. For one graphics card and one fast SSD, the two perform the same.
A520 removes CPU overclocking and PCIe 4.0 entirely, and A520 boards are generally more basic. If the price gap is small, B550 is the better buy for a Ryzen 5 5600 or above.
B450 is the older alternative. It supports the early Ryzen chips that B550 does not, but it is limited to PCIe 3.0.
Whether B550 is still worth buying
For a new build from nothing, look at AM5 first. It uses DDR5, has PCIe 5.0 on many boards, and AMD has said it is supported through 2027 and beyond. AM5 vs AM4 compares the two routes.
B550 makes sense in two cases. One is replacing a failed board while keeping your Ryzen processor and DDR4. The other is upgrading an older AM4 system: a B550 board with a Ryzen 5000 chip, reusing your memory, is one of the cheaper ways to a capable gaming PC. In both cases you are buying a 2020 design, so a reduced or Warehouse board is a sensible way to do it. AM4 processors carry the pins, so the board's socket is less fragile than AM5's, which lowers one of the usual risks of opened stock. Our Warehouse guide covers the others.
What varies by board
- Power delivery: B550 ranges from basic boards to ones built for a 16-core Ryzen 9. See VRMs explained.
- Number of M.2 slots, and whether any SATA ports are disabled when the second one is used.
- WiFi: usually WiFi 6 where fitted, often as a separate model.
- Rear USB count and whether there is a USB-C port.
- Size: ATX, micro-ATX and mini-ITX boards were all made.
What to check on the listing
- Your exact processor on the board's CPU support list.
- A BIOS flashback button, if you are fitting Ryzen 5000 to a board of unknown age.
- WIFI or non-WIFI version, and revision suffixes such as V2 or II.
- Form factor against your case.
Reductions are on the B550 deals list, each judged against that board's own price history. Opened-box offers are on the Warehouse page.
Questions people ask
Does B550 support Ryzen 5000 processors?
Yes. Boards made in 2020, before Ryzen 5000 was released, need a BIOS update first. A BIOS flashback button lets you do that without an older processor.
Can I use a Ryzen 5 2600 or Ryzen 5 3400G in a B550 board?
No. B550 does not officially support Ryzen 1000 or Ryzen 2000 processors, or the older G-series chips such as the 3200G and 3400G. B450 is the usual home for those chips, and X570 supports Ryzen 2000. Check the CPU support list of the specific board.
Does B550 have PCIe 4.0?
Yes, for the graphics slot and the main M.2 slot, which connect to the processor. The chipset lanes are PCIe 3.0. You also need a Ryzen 3000 or 5000 processor without integrated graphics; G-series chips run the board at PCIe 3.0.
Can you overclock on B550?
Yes. B550 allows CPU and memory overclocking. A520 allows memory overclocking only.