Lekuo SouthBridge Max PCIe 4.0 Multi-Function Expansion Card
The PB65MX3 is a PCIe 4.0 x4 expansion card that delivers 4× M.2 NVMe + 4× SATA 6G + 2× USB-A 10G + 1× USB-C 10G + 1× USB-C 20G — a total of 12 expansion interfaces. It supports Windows, Linux, and macOS, making it ideal for NAS enthusiasts, video/audio editing workstations, high-end PC users, and anyone needing multi-drive storage plus extensive peripheral expansion.
Why Is It So Hard to Add More Drives?
When you want to attach more drives or high-speed ports to your system, you typically run into three obstacles:
- Motherboards have limited M.2 slots. Most consumer boards come with only 1–2 M.2 slots, so aiming for a 4-drive setup is often stopped before it starts.
- M.2 expansion cards often only recognise a single drive — because these cards usually require the motherboard to support PCIe bifurcation, and many boards (especially older platforms) do not.
- NAS, video, and audio production workloads demand 4 or more drives plus high-speed peripherals, but stock motherboard ports are frequently insufficient. Front-panel USB ports are perpetually in short supply, and 20G high-speed ports are even rarer.
What Is the PB65MX3?
In a nutshell: it uses a single PCIe 4.0 x4 slot to expand into 12 interfaces.
Key Feature: No Motherboard Bifurcation Required
Standard M.2 expansion cards require the motherboard to support PCIe bifurcation in order to recognise multiple drives. The PB65MX3, however, offloads this task to the B650 south bridge's internal channel allocation, meaning it does not rely on motherboard bifurcation support. For users with older platforms or mainstream consumer boards, this is the difference between "plug and play" and "plug and only see one drive."
M.2 Intelligent Bandwidth Allocation Logic
- With only the two front drives populated (M.2_A, M.2_C): both run at x4 links.
- With all four drives populated: all four M.2 interfaces automatically adjust to x2 links.
How It Differs from Regular Expansion Cards
Standard M.2 expansion cards depend on motherboard PCIe bifurcation support, which older or mainstream consumer boards often lack. The PB65MX3 integrates the B650 south bridge channel allocation scheme internally, so it works with any motherboard — plug it in and it just works.
Who Is It For?
- NAS enthusiasts: 4× M.2 + 4× SATA lets you set up cache drives and data drives in one go.
- Video/audio editing workstations: Parallel read/write across multiple drives, plus a 20G USB-C port for high-speed peripherals.
- High-end PC users: Once your motherboard slots are full, use a single x4 slot to keep expanding.
- Multi-peripheral scenarios: 10G/20G USB ports provide ample bandwidth for high-speed capture cards and portable SSDs.
Frequently Asked Questions
Q: My motherboard doesn't support PCIe bifurcation. Will this work?
✅ Yes. The PB65MX3 uses the B650 south bridge's built-in channel allocation and does not rely on motherboard bifurcation support.
Q: What happens to speed when all four M.2 slots are populated?
✅ The two front slots (M.2_A, M.2_C) support x4, while the two rear slots (M.2_B, M.2_D) support x2. When all four are populated, all interfaces run at x2 links.
Q: Which operating systems are supported?
✅ Windows, Linux, and macOS are all supported.
Summary
The LEKUO PB65MX3 is a PCIe 4.0 x4 expansion card that, through its integrated B650 south bridge channel allocation scheme, delivers no-bifurcation-required plug-and-play operation. A single card expands to 4× M.2 NVMe + 4× SATA 6G + 2× USB-A 10G + 1× USB-C 10G + 1× USB-C 20G — 12 interfaces in total. It is well suited for NAS multi-drive storage, video/audio editing workstations, high-end PC upgrades, and other scenarios, offering a practical solution to motherboard port shortages and PCIe bifurcation limitations.