P55329-B21 HPE MLX Broadcom 100Gbps Single-Port SPI Adapter

Product Overview of P55329-B21 HPE 100Gbps 1-Port Adapter

The HPE P55329-B21 MLX Broadcom 100Gbps Single-Port OCP3 SPI Network Adapter is a high-performance networking solution engineered for modern data centers and enterprise server environments. It delivers ultra-fast connectivity, low latency, and reliable throughput to support demanding workloads such as cloud computing, virtualization, and high-performance networking.

General Information

• Brand: Hewlett Packard Enterprise (HPE)
• Manufacturer Part Number: P55329-B21
• Device Category: Network Adapter Card

Form Factor and Interface

• Form Factor: OCP 3.0 (Open Compute Project)
• Interface Type: SPI (Small Peripheral Interconnect)
• Compact and modular design for optimized airflow and space efficiency

Key Features and Highlights

• Ultra-high-speed networking with up to 100 Gbps data transfer rate
• Single-port design optimized for bandwidth-intensive applications
• Built on Broadcom chipset technology for stable and efficient performance
• Energy-efficient architecture suitable for enterprise-grade servers

Compatibility and Use Cases

• Enterprise data centers
• Cloud and virtualization infrastructures
• High-performance computing (HPC)
• Storage and database-intensive applications

Advantages of This Network Adapter

• Delivers consistent 100Gbps high-speed connectivity
• Optimized for modern server architectures
• Trusted HPE quality and Broadcom technology
• Enhances overall network efficiency and scalability

Understanding the OCP 3.0 SPI Form Factor Advantage

The OCP (Open Compute Project) form factor represents a significant shift from traditional PCIe add-in cards. The HPE P55329-B21 adheres specifically to the OCP 3.0 Small Profile (SPI) specification, which offers distinct advantages in dense server deployments.

OCP 3.0 SPI is a mezzanine card design that mounts directly onto a dedicated connector on the server motherboard, typically positioned parallel to the system board. This design eliminates the need for a full-height or full-length PCIe slot, freeing up valuable expansion space for other accelerators like GPUs or FPGAs. The "SPI" designation indicates a smaller physical footprint compared to the larger "L" (Large) profile, making it ideal for 1U and dense 2U server configurations where every millimeter counts.

Key Benefits for Server Integration

The integration of an OCP NIC like the P55329-B21 streamlines server manufacturing and improves overall system reliability. With a direct, soldered connection to the motherboard via a high-speed edge connector, signal integrity is enhanced, reducing potential points of failure compared to a traditional PCIe card in a socket. This design also improves airflow management within the chassis, as the card's profile is much lower. For data center operators, this means predictable, vendor-validated compatibility with HPE ProLiant Gen10 Plus and Gen11 platforms that support OCP 3.0, ensuring optimal performance and simplifying procurement and maintenance cycles.

Deep Dive: Broadcom NetXtreme®-E BCM57416 Controller Architecture

The true power of the HPE P55329-B21 adapter is derived from its silicon heart: the Broadcom BCM57416 NetXtreme-E 100Gb Ethernet controller. This ASIC is engineered for extreme performance and efficiency, incorporating several advanced technologies that offload work from the server CPU.

Enhanced Ethernet Offloads (Tunneling & VXLAN)

In virtualized and cloud environments, network overlay protocols like VXLAN, NVGRE, and GENEVE are essential for creating scalable, multi-tenant networks. The BCM57416 controller features robust hardware offloads for these encapsulation protocols. By performing encapsulation and decapsulation in dedicated hardware on the NIC itself, the adapter dramatically reduces the CPU overhead associated with software-based tunneling. This allows host CPUs to dedicate more cycles to application workloads, increasing overall virtual machine density and improving performance for software-defined networking (SDN) and network virtualization.

Advanced RDMA over Converged Ethernet (RoCE v2) Support

One of the most critical features for high-performance computing and storage is RDMA over Converged Ethernet version 2 (RoCE v2). RoCE allows for direct memory access between servers' memory across the network, bypassing the operating system kernel and TCP/IP stack. This results in ultra-low latency and near-zero CPU utilization during data transfers. The P55329-B21's RoCE v2 implementation is vital for:

Storage Acceleration: Enabling high-performance solutions like NVMe-of-TCP and NVMe-of-RDMA, breaking storage performance bottlenecks.
AI/ML Clusters: Accelerating gradient exchange and model synchronization in distributed machine learning training jobs.
Financial Trading Systems: Where microseconds of latency translate to significant financial advantage.

Precision Time Protocol (PTP) and Network Timing

For applications requiring precise synchronization, such as 5G telecommunication infrastructures, broadcast media, and distributed databases, the adapter provides hardware-assisted support for IEEE 1588 Precision Time Protocol. This allows servers in a cluster to synchronize their clocks with sub-microsecond accuracy, ensuring coordinated actions and consistent data ordering across the network.

Performance Specifications and Use Case Elaboration

The HPE P55329-B21 is engineered to deliver consistent, line-rate performance, making it suitable for the most demanding network environments.

Bandwidth and Interface Details

This is a single-port 100GBASE-SR4 QSFP28 network adapter. The QSFP28 (Quad Small Form-factor Pluggable 28) transceiver interface is the industry standard for 100Gbps connectivity. The "SR4" designation in the model name indicates it is optimized for multi-mode fiber (MMF) connections using four parallel lanes of 25Gbps each. It typically uses an MPO-12 connector for short-reach, high-density data center cabling within a rack or between adjacent racks, supporting distances up to 100 meters over OM4 fiber.

Ideal Deployment Scenarios

The combination of 100Gbps bandwidth, OCP form factor, and advanced offloads makes the P55329-B21 a targeted solution for specific high-growth areas:

Hyper-Converged Infrastructure (HCI) Backbone

In HCI platforms like HPE SimpliVity or VMware vSAN, the network is the backbone for all east-west traffic between nodes, handling virtual machine communication, storage replication, and migration flows. The adapter’s RoCE capabilities can dramatically speed up storage I/O, while its offloads free up CPU resources for compute tasks, leading to more predictable performance and higher consolidation ratios.

High-Performance Computing (HPC)

HPC clusters require low-latency, high-bandwidth interconnects for message-passing interface (MPI) traffic. The adapter’s RDMA support is crucial here, enabling frameworks like MPI to directly access remote memory, drastically reducing communication latency between compute nodes during complex simulations, genomic analysis, or AI model training.

Data Center Spine-Leaf Interconnect

As top-of-rack (ToR) switches evolve to support 100G uplinks, servers with native 100G OCP adapters like the P55329-B21 can connect directly to these high-speed leaf switches, creating a streamlined, high-bandwidth path to the network spine. This eliminates bottlenecks and future-proofs server connectivity for several generations.

Compatibility, Management, and Software Ecosystem

Seamless integration into the HPE ecosystem is a hallmark of the P55329-B21 adapter.

Supported HPE Server Platforms

This OCP NIC is specifically validated and qualified for use in HPE ProLiant servers that feature an OCP 3.0 connector. Key compatible platforms include the HPE ProLiant DL360 Gen10 Plus, DL380 Gen10 Plus, DL325 Gen10 Plus, and their subsequent Gen11 equivalents. It is imperative to verify the specific server's OCP support and configuration guide, as the OCP slot may share resources with certain PCIe slots.

Unified Driver and Firmware Management with HPE iLO

The adapter is fully supported by HPE's integrated Lights-Out (iLO) management suite. Administrators can view adapter health, status, and firmware versions directly from the iLO web interface. Firmware updates for the NIC can be bundled and deployed as part of the server's SPP (Service Pack for ProLiant), ensuring consistency and reducing the risk of incompatibility. Broadcom's UEFI-enabled Unified Network Driver (UNDI) and the standard `bnxt_en` Linux driver provide robust, performance-tuned support across Windows Server, VMware ESXi, and major Linux distributions.

SmartANIC and HPE OneView Integration

As part of HPE's portfolio, the adapter can be managed within broader infrastructure automation tools like HPE OneView. Its telemetry data can contribute to composable infrastructure profiles, allowing for dynamic resource assignment based on workload requirements.

Comparison and Strategic Positioning

Understanding where the P55329-B21 fits within HPE's broader networking portfolio helps in making an informed selection.

P55329-B21 vs. PCIe-Based 100G Adapters

Compared to a PCIe-based HPE 100G adapter, the P55329-B21 offers identical performance but with the inherent OCP advantages: space savings, improved signal integrity, and streamlined server integration. The choice often comes down to server model: platforms with OCP 3.0 slots benefit from the mezzanine design, while older or expansion-heavy servers might require a PCIe card.

Single-Port vs. Dual-Port OCP Adapters

HPE also offers dual-port 25GbE and 100GbE OCP adapters. The single-port P55329-B21 is ideal for applications where maximum bandwidth to a single network fabric is the goal, such as a dedicated storage or compute network. Dual-port adapters provide redundancy and link aggregation but may split resources. For a server requiring a single, ultra-fast uplink to a 100G leaf switch, the P55329-B21 is a cost-effective and performant solution.

The Roadmap Context: 100G as the New Workhorse

While 200G and 400G technologies are emerging for spine and super-spine layers, 100G is becoming the standard server access speed for tier-1 applications, succeeding 10G and 25G. Investing in 100G OCP adapters like the P55329-B21 future-proofs HPE server deployments, ensuring they are not the bottleneck in the data center network for years to come. It represents the optimal balance of performance, density, cost, and power efficiency for the majority of high-throughput workloads today.