The **M2XPA3-B4V2-R** is a high-performance M.2 NVMe SSD expansion card (often referred to as a "Bifurcation Card" or "RAID Card") designed by **ASRock Rack**. This component allows a user to split a single PCIe 3.0 x16 slot into four M.2 slots. --- ### 1. Key Technical Specifications | Feature | Specification | | :--- | :--- | | **Interface** | PCIe 3.0 x16 | | **Storage Slots** | 4 x M.2 (M-Key) | | **SSD Form Factor** | 2242, 2260, 2280, 22110 | | **Data Transfer Rate** | Up to 128 Gbps (32 Gbps per slot) | | **Required BIOS Mode** | PCIe Slot Bifurcation (x4x4x4x4) | --- ### 2. Core Electronic Components The "B4V2" revision focuses on power stability and signal integrity. Here are the primary electronic elements found on the PCB: #### A. Power Management Integrated Circuits (PMICs) Because NVMe drives can draw significant current (up to 2.5A - 3A per drive during peak writes), the board features dedicated **DC-to-DC step-down converters**. - These convert the 12V rail from the PCIe slot down to the **3.3V** required by M.2 SSDs. - High-quality solid capacitors are used to filter ripple noise and ensure stable voltage delivery. #### B. Signal Redrivers / Retimers To maintain high-speed PCIe 3.0 signal integrity over the distance from the motherboard slot to the furthest M.2 connector, the board utilizes **Redrivers**. These chips amplify the signal to prevent data corruption or drops in transfer speeds. #### C. PCIe Bifurcation Logic Unlike expensive RAID cards, this board is "passive" or "semi-passive." It does not have an onboard RAID controller chip (like a Marvell or Broadcom chip). - **Electronic Requirement:** It relies on the CPU/Motherboard BIOS to support **PCIe Bifurcation**. - The board uses a series of resistors and traces to map the x16 lanes into four distinct x4 channels. --- ### 3. Physical Layout and Connectivity ```mermaid graph LR PCIe_x16[PCIe x16 Slot] --> Ch1[M.2 Slot 1 - x4] PCIe_x16 --> Ch2[M.2 Slot 2 - x4] PCIe_x16 --> Ch3[M.2 Slot 3 - x4] PCIe_x16 --> Ch4[M.2 Slot 4 - x4] ``` 1. **M.2 Connectors:** Gold-plated pins to minimize resistance and oxidation. 2. **Thermal Pads/Heatsink:** Usually equipped with a full-length aluminum cover to dissipate heat from the controller chips of the SSDs. 3. **Activity LEDs:** Small Surface Mount (SMD) LEDs that flicker based on the "Drive Active" signal from the M.2 pins. --- ### 4. Compatibility Warning The M2XPA3-B4V2-R is an electronic bridge. If your motherboard's BIOS does not support splitting the x16 slot into **x4/x4/x4/x4**, the system will only detect **one** SSD (the first slot), even if all four are populated.