Even the best motherboards often present connectivity and expansion challenges, particularly in compact form factors. A new PCIe AIC (Add-In Card) is an effective solution. There's an open-source project titled “AMD B650 Southbridge Expansion Card,” hosted on OSHWHub, that provides an interesting option to enable substantial expansion of your motherboard’s storage capabilities.
It is not the first time a manufacturer has developed an AIC based on an AMD chipset. Previously, ASRock introduced the “X670 Xpansion Kit,” a specialized expansion card designed for its B650 LiveMixer motherboard. This add-in card, which also uses the B650 chipset, elevates the B650 LiveMixer to the feature set of an X670-class motherboard.
For context, the X670 motherboard is equipped with two AMD Promontory 21 chipsets, while the more cost-effective B650 motherboards include only one. By incorporating an additional chipset via the AIC, the B650 LiveMixer can provide features and capabilities comparable to those of higher-end X670 models. Hardware enthusiast Uniko's Hardware quickly reminded us that Asus used a similar approach, placing an X670 chipset on an M.2 daughterboard that plugs into the ROG Strix X670E-I Gaming WiFi, a mini-ITX motherboard. In contrast, the AMD B650 Southbridge Expansion Card is a community-driven project hosted on OSHWHub, a platform dedicated to sharing and collaborating on hardware designs.
The AMD B650 Southbridge Expansion Card interfaces with the host system via a standard PCIe 4.0 x4 connector. Notably, this expansion card is compatible with both Intel and AMD platforms, provided the system includes an available PCIe 4.0 x4 expansion slot. The expansion card features four SATA III ports, two PCIe 4.0 x4 slots, and one USB 3.2 Gen 2x2 header.
Benchmark results confirm that all storage ports deliver excellent performance. PCIe 4.0 SSDs achieved sequential read speeds just above 6,900 MB/s and write speeds exceeding 6,400 MB/s. SATA drives demonstrated consistent sequential read and write speeds above 500 MB/s. The USB 3.2 Gen 2x2 port recorded sequential read speeds above 2,000 MB/s and write speeds over 1,900 MB/s.
Schematics, a parts list, and comprehensive instructions for building the AMD B650 Southbridge Expansion Card are available at no cost. The author notes that you must flash the card with a special firmware for proper functionality. While the firmware is not publicly hosted, you can obtain it for free by joining the creator's QQ group.
According to the author, you can replicate the AMD B650 Southbridge Expansion Card for approximately 300 yuan (about $42.88). Although the expansion card is not commercially available, OSHWHub has integrated manufacturing services through its sister company, JLCPCB. It allows you to order custom hardware directly using the design files shared on OSHWHub, and JLCPCB will manufacture it.
Stay On the Cutting Edge: Get the Tom's Hardware Newsletter Get Tom's Hardware's best news and in-depth reviews, straight to your inbox. Contact me with news and offers from other Future brands Receive email from us on behalf of our trusted partners or sponsors
Follow Tom's Hardware on Google News, or add us as a preferred source, to get our latest news, analysis, & reviews in your feeds.