ASRock Rack DMRD16 2L Image © ServethehomeASRock Rack DMRD16 2L (Image © Servethehome)

The DMRD16-2L+ uses the EEB form factor, measuring 304 x 330 mm. It features sixteen memory slots arranged in a “1DPC” layout (one DIMM per channel) around the CPU socket. The board supports three different types of memory modules:

  • RDIMMs: Support for capacities up to 128 GB at a maximum speed of 8,000 MT/s.
  • MRDIMMs: Support for capacities up to 128 GB at a maximum speed of 12,800 MT/s.
  • MRDIMM-2U modules: Support for capacities up to 256 GB at a maximum speed of 12,800 MT/s.

The CPU socket is equipped with a special cover that uses a twist-lock mechanism to secure the processor.

ASRock Rack DMRD16 2L MCIOASRock Rack DMRD16 2L MCIO (Image © Servethehome)

Connectors and MCIO Integration

The DMRD16-2L+ stands out in particular due to the absence of standard PCIe CEM card slots and OCP NIC 3.0 connectors. Instead, the motherboard relies entirely on MCIO connectivity for its external I/O. The board offers up to 16 MCIO x8 ports on the I/O side. Each of these ports is designed for either PCIe 6.0 or CXL 3.0 at x8 speed, providing a total of 128 PCIe Gen 6 or CXL 3.0 lanes. This design decision reflects a broader industry trend toward wired connectivity to mitigate the signal transmission issues associated with PCIe Gen6.

Storage and System Management

For local booting and storage, the motherboard features a single M-Key M.2 slot. This slot supports PCIe 5.0 x4 and is compatible with the M.2 form factors 22110, 2280, and 2260. System management is handled by an ASPEED AST2700 BMC. The board also features a dedicated IPMI port controlled by a Realtek RTL8211F controller, as well as two RJ45 1GbE ports managed by an Intel I350 controller for basic network access.

Interfaces and Internal Connectors

The rear I/O panel consists of two USB 3.2 Gen 1 Type-A ports and a DB15 VGA port. Internal connectivity is expanded via the following ports:

  • Two additional USB 3.2 Gen 1 ports via a 19-pin connector.
  • An internal video connector.
  • A COM connector.
  • Support for a 13-pin SPI TPM module.

The layout emphasizes a high-density configuration in which sixteen memory channels and extensive Gen6 I/O ports are concentrated around a single CPU socket, reflecting the scale of the Diamond Rapids architecture.