Whereas the B450 chipset offers 8 PCIe 2.0 lanes, the B550 chipset offers 10 PCIe 3.0 lanes. Both use a PCIe 3.0 x4 link to the CPU, but the lanes offered by the chipset are different. As noted earlier, PCIe 4.0 support is provided by the CPU, but the chipset still has its own PCIe lanes, 8 in the case of B450 and 10 on B550.
Now, the next most important upgrade on the B550 chipset has to do with the PCI Express lanes made available via the chipset itself. That’s not to say PCIe 4.0 won’t be important to have in the future, but it's a technology that’s better suited to high-end systems using an X570 motherboard or HEDT systems using expensive Threadripper CPUs.
When it comes to PCIe 4.0 storage, the gains look good on paper and are certainly good for raw file transfers, but when talking about general PC usage and gaming, the difference between a good NVMe SSD running in PCIe 4.0 and 3.0 mode is virtually nil. Even the RTX 3090 only gains about 3% more performance on average at low resolutions. As it stands, neither feature is terribly advantageous to most consumers as PCIe 4.0 has yet to offer any kind of performance advantage for graphics cards. We won’t get into that here, but the point is PCIe 4.0 support on B550 boards comes from the CPU, not the chipset itself.Īll AMD B550 motherboards only support PCIe 4.0 for the primary PCIe x16 slot for graphics cards, as well as PCIe 4.0 for the primary M.2 slot for high speed storage. In fact, we’ve seen BIOS revisions from the likes of Gigabyte which enabled PCIe 4.0 operation on B450 boards, but that was later removed due to pressure from AMD. Technically speaking, there’s no reason why B450 boards can’t offer the same level of PCIe 4.0 support as B550 boards, as that support comes directly from the Ryzen 3000 processors, they’re just using the 20 PCIe 4.0 lanes from the CPU. The key advantages of the AMD B550 chipset is PCI Express 4.0, but this is a little confusing as this feature isn’t actually enabled by the chipset.
which we should add, aren’t supported on B450 boards as far as we’re aware.
Compare that to the B550 chipset which only officially supports the Ryzen 3000 and the upcoming 5000 series, though please note the Ryzen 3000 series APUs such as the 3200G and 3400G aren’t supported on B550 boards, APU support is limited to Renoir APUs, that's the Ryzen 4000 series. That means processor support on B450 motherboards includes Ryzen 1000, 2000, 3000 and now the upcoming 5000 series, though a single BIOS revision is unlikely to support them all. However, due to push back from the community and publications like ours where we strongly suggested AMD to reconsider, they quickly walked back the decision and announced that the 400 series boards (B450 and X470) would receive support for Zen 3 processors, now known as the Ryzen 5000 series. You may recall AMD originally announced they’d be axing support for Zen 3 on all 300 and 400 series motherboards. In this article we'll explain how these chipsets differ and talk about why you may or may not need to upgrade for supporting a Zen 3 processor. It seems many prospective buyers aren’t clear on the differences between these chipsets and as a result we’ve seen many current B450 owners concerned about what they should do in regards to whether or not they need to upgrade. With the announcement of AMD's Ryzen 5000 desktop CPU series, we noticed a lot of chatter about B450 and B550 motherboards.