Microchip Technology PM8265B-F3EI

Overview

PM8265B-F3EI from Microchip is a tri-mode PCIe Gen 4 storage controller supporting NVMe, SAS-4 (24 Gbps), and SATA protocols with 8 host lanes and 16 disk lanes, hardware-based AES-256 encryption, and integrated Switchtec PCIe Gen 4 switch for low-latency NVMe RAID in enterprise rack servers.

For engineers reviewing the PM8265B-F3EI datasheet, PM8265B-F3EI pinout, PM8265B-F3EI application, or PM8265B-F3EI equivalent, key selection criteria include tri-mode lane allocation, DCM-enabled SAS-4 bandwidth aggregation, DDR4-3200 memory interface width, PCIe Gen 4 x8 host connectivity, and hardware root-of-trust for Secure Boot and firmware integrity verification.

Technical Context

The PM8265B-F3EI implements a fully integrated PCIe Gen 4 switch with x1–x8 bifurcation support and dynamic channel multiplexing (DCM) to aggregate SAS/SATA drive bandwidth over 24 Gbps SAS-4 links. It delivers native HBA, RAID, and transparent NVMe modes per drive with end-to-end error containment including poisoned TLP blocking and completion timeout synthesis.

Hardware root-of-trust enables signed Secure Boot and authenticated Secure Update, while the 72-bit DDR4-3200 memory interface supports caching and metadata management. The device operates within SFF-TA-1001-compliant universal bay architectures and interfaces directly with Microchip SXP 24G SAS-4 expanders.

Key Specifications

Pinout & Package

PM8265B-F3EI is housed in a 25 mm × 25 mm, 0.8 mm pitch, 900-pin FCBGA package. Pin assignment follows Microchip's SmartROC 3200e family layout with dedicated banks for PCIe differential pairs, SAS-4 SERDES lanes, DDR4 DQ/DQS/DM signals, power delivery, and management interfaces (I²C, SPI, JTAG).

Key Features

Applications

Equivalent & Alternatives

The following parts are listed as comparable options for similar tri-mode storage controller applications.

Compared with PM8264B-F3EI, PM8265B-F3EI adds mandatory AES-256 encryption without altering pinout or memory interface; compared with PM8273B-F3EI, it trades host/disk lane symmetry and package size for compact 8×16 topology-making it optimal for space-constrained 2U servers with asymmetric storage scaling needs.

Availability

PM8265B-F3EI is available at Aetrix Electronics and suitable for enterprise rack servers, universal bay architectures, externally connected JBOD expansion systems, and encrypted caching HBA deployments requiring stable component supply and long-term lifecycle support.

Supply support for PM8265B-F3EI includes scheduled delivery planning, volume procurement assistance, BOM continuity management, traceable sourcing, and lifecycle availability coordination for OEM customers, industrial embedded developers, connected-device designers, and electronics production programs.

Manufacturer

Microchip Technology is a U.S.-based semiconductor company specializing in microcontrollers, analog devices, FPGAs, and storage controllers with emphasis on security, reliability, and long-life product support.

The SmartROC 3200e product line delivers secure, tri-mode storage control for enterprise data centers-designed specifically to unify NVMe, SAS, and SATA media under a single, encrypted, and standards-compliant architecture.

FAQ

What is the primary function of the PM8265B-F3EI in a server storage system?

The PM8265B-F3EI serves as a tri-mode RAID-on-chip controller that manages NVMe, SAS-4, and SATA storage media simultaneously. It integrates PCIe Gen 4 switching, hardware AES-256 encryption, DDR4-3200 memory interface, and Dynamic Channel Multiplexing. In a server, the PM8265B-F3EI handles I/O routing, RAID processing, encryption offload, and SAS-4 expansion-eliminating need for discrete switches or encryption accelerators. Its role is central to secure, high-density, protocol-agnostic storage subsystems.

Does the PM8265B-F3EI support PCIe Gen 4 x8 host connectivity and how does it impact performance?

Yes, the PM8265B-F3EI supports PCIe Gen 4 x8 host interface delivering up to 32 GB/s bidirectional bandwidth. This enables full utilization of high-throughput NVMe SSDs and minimizes I/O bottlenecks in RAID 5/6 configurations. The integrated Switchtec PCIe switch ensures sub-300 ns latency between host and NVMe targets, and supports x1–x8 bifurcation to match diverse SSD form factors. This host interface directly determines maximum achievable sequential read/write throughput and concurrent queue depth scalability in the PM8265B-F3EI-based design.

How does Dynamic Channel Multiplexing (DCM) operate on the PM8265B-F3EI and what benefit does it provide?

DCM on the PM8265B-F3EI aggregates bandwidth from multiple lower-speed SAS or SATA drives onto a single 24 Gbps SAS-4 link-for example, combining eight 6 Gbps SATA drives into one fully utilized SAS-4 channel. It operates transparently at the PHY layer without host or driver involvement. The benefit is near 100% SAS-4 link efficiency in JBOD expansion scenarios, reducing required expander ports and cabling while extending compatibility with legacy storage assets. DCM is enabled only when connected to Microchip SXP 24G SAS-4 expanders and is a confirmed feature of the PM8265B-F3EI.

Is hardware-based AES-256 encryption standard on the PM8265B-F3EI and how is it implemented?

Yes, hardware AES-256 encryption is standard and enabled on the PM8265B-F3EI-unlike the non-"e" variant PM8264B-F3EI. It is implemented via a dedicated on-die cryptographic engine that performs inline encryption/decryption of all data-at-rest across NVMe, SAS-4, and SATA media. Keys are managed through the controller's secure key store, and encryption operates transparently to the host OS and drivers. No CPU cycles or software stack involvement is required, ensuring consistent I/O performance regardless of encryption state in the PM8265B-F3EI.

What memory interface does the PM8265B-F3EI use and why is the 72-bit width significant?

The PM8265B-F3EI uses a 72-bit DDR4-3200 interface supporting data rates up to 25.6 GB/s. The 72-bit width includes 64 data bits plus 8 ECC bits, enabling single-bit error correction and double-bit error detection for memory-resident RAID parity tables, caching metadata, and firmware execution. This ECC-integrated width ensures data integrity for critical storage operations-especially during high-concurrency RAID 5/6 rebuilds-and is a defined specification for the PM8265B-F3EI, distinguishing it from variants with 144-bit interfaces.