> For the complete documentation index, see [llms.txt](https://wiki.wisdpi.com/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://wiki.wisdpi.com/computer/wisdpi-prom21-all-in-expansion-card.md).

# WisdPi PROM21 All in Expansion Card

The PROM21 All in is a flagship PCIe x4 expansion card powered directly by the AMD B650 (Promontory 21) desktop chipset. It delivers desktop-grade I/O bandwidth, massive storage capacity, and next-gen connectivity to any workstation or high-performance PC.

Standard usage

<figure><img src="/files/YjOitbv6KORSfMSd2FDj" alt=""><figcaption></figcaption></figure>

## Features

* Desktop Chipset Power: Built around the AMD B650 chipset for rock-solid stability and massive data throughput over a single PCIe x4 slot.
* Switchable Oculink Port: Features a versatile Oculink interface that multiplexes PCIe and SATA signals. Easily switch between configurations via the onboard DIP switch (SW1) to support external GPUs or enterprise storage arrays.
* Quad M.2 Storage Matrix: Equipped with 4x M.2 slots (2 on the front, 2 on the rear). Maximize your storage capacity with support for high-speed NVMe and SATA SSDs using the chipset's dedicated downstream lanes.
* High-Speed USB Hub: Rear I/O includes a blisteringly fast 20Gbps USB-C port alongside four 10Gbps USB-A ports for zero-bottleneck peripheral connections.
* Robust Power & Cooling: Features a dedicated external power connector (EXT\_PWR) to ensure stable voltage under heavy loads, paired with a custom aluminum heatsink and a dedicated cooling fan header.

## Spec

| **Feature**       | **Specification**                                                                |
| ----------------- | -------------------------------------------------------------------------------- |
| Controller        | AMD Promontory 21 (B650 Chipset)                                                 |
| Host Interface    | PCIe 4.0 x4                                                                      |
| Storage Expansion | 4x M.2 Slots                                                                     |
| Next-Gen I/O      | 1x Oculink Port (Multiplexed PCIe/SATA)                                          |
| External USB      | <p>1x USB 3.2 Gen 2x2 Type-C (20Gbps)</p><p>4x USB 3.2 Gen 2 Type-A (10Gbps)</p> |
| Internal USB      | 6x USB 2.0 front panel header                                                    |
| Power Delivery    | PCIe Slot Power + ext power connector                                            |
| Cooling           | Aluminum Heatsink with onboard Fan Header                                        |
| Compatibility     | x86(AMD/Intel) / ARM(Mac Silicon Series/Raspberry Pi 5) standard PCIe            |
| Size              | 175x70mm                                                                         |

## I/O Functions

<figure><img src="/files/LsDc2hS4XntOzQoFmjcT" alt=""><figcaption></figcaption></figure>

<figure><img src="/files/00yCVFDHP1Zs4uv3uR2o" alt=""><figcaption></figcaption></figure>

<table><thead><tr><th width="69">No</th><th width="195.0001220703125">Silk</th><th>Description</th></tr></thead><tbody><tr><td>1</td><td>EXT_PWR for USB</td><td>12V PCIe 6-Pin Power Connector. <strong>To use the USB port, this power supply must be connected.</strong></td></tr><tr><td>2</td><td>20G USBC1</td><td>USB 3.2 Gen2 x2 20Gbps port x1</td></tr><tr><td>3</td><td>10G USBA1~4</td><td>USB 3.2 Gen2 10Gbps port x4</td></tr><tr><td>4</td><td>HS USBA5~10</td><td>Front Panel USB 2.0 Header 480Mbps port x6</td></tr><tr><td>5</td><td>PCIe/SATA Oculink</td><td>Oculink (SFF-8611) port config by SW1</td></tr><tr><td>6</td><td>M.2_3</td><td>M.2 M-Key 2280/22110 PCIe 4.0 x4*</td></tr><tr><td>7</td><td>M.2_1</td><td>M.2 M-Key 2280/22110 PCIe 4.0 x4*</td></tr><tr><td>8</td><td>FAN</td><td>12V FAN power connector</td></tr><tr><td>9</td><td>SATA LED1~4</td><td>Data status of SATA 1~4 port</td></tr><tr><td>10</td><td>M.2 LED1~4</td><td>Data status of M.2 1~4 port</td></tr><tr><td>11</td><td>SW1</td><td>Oculink port configuration switch</td></tr><tr><td>12</td><td>M.2_4</td><td>M.2 M-Key PCIe 4.0 x2</td></tr><tr><td>13</td><td>M.2_2</td><td>M.2 M-Key PCIe 4.0 x2</td></tr></tbody></table>

> **\*Note: If M.2\_2 and/or M.2\_4 are in use, M.2\_1 and M.2\_3 will automatically drop to x2 lanes mode.**

## Oculink (SFF-8611) port configuration (SW1)

<figure><img src="/files/39vvvseX0tNmDNb91tMT" alt=""><figcaption></figcaption></figure>

## M.2 slot lane distribution

* M.2\_1 & M.2\_3: Support PCIe x4 lanes (standalone mode).
* M.2\_2 & M.2\_4: Support PCIe x2 lanes.

> **Note: If M.2\_2 and/or M.2\_4 are in use, M.2\_1 and M.2\_3 will automatically drop to x2 lanes mode.**

<table><thead><tr><th>M.2_1</th><th width="187">M.2_2</th><th>M.2_3</th><th>M.2_4</th></tr></thead><tbody><tr><td>4.0 x4</td><td>/</td><td>4.0 x4</td><td>/</td></tr><tr><td>4.0 x2 </td><td>4.0 x2 </td><td>4.0 x2 </td><td>4.0 x2 </td></tr></tbody></table>


---

# Agent Instructions
This documentation is published with GitBook. GitBook is the documentation platform designed so that both humans and AI agents can read, navigate, and reason over technical content effectively. Learn more at gitbook.com.

## Querying This Documentation
If you need additional information that is not directly available in this page, you can query the documentation dynamically by asking a question.

Perform an HTTP GET request on the current page URL with the `ask` query parameter, and the optional `goal` query parameter:

```
GET https://wiki.wisdpi.com/computer/wisdpi-prom21-all-in-expansion-card.md?ask=<question>&goal=<endgoal>
```

`ask` is the immediate question: it should be specific, self-contained, and written in natural language.
`goal` is optional and describes the broader end goal you are ultimately trying to accomplish on behalf of the user. GitBook uses it to tailor the answer towards what is most useful for that goal.

The response will contain a direct answer to the question and relevant excerpts and sources from the documentation.

Use this mechanism when the answer is not explicitly present in the current page, you need clarification or additional context, or you want to retrieve related documentation sections.