W2C1K Dell PERC H965i Front RAID Controller.

Dell W2C1K PERC H965i — High-Performance Front Internal RAID Controller

The Dell W2C1K PERC H965i is a purpose-built front-mounted storage controller engineered for enterprise servers that demand robust data protection, fast throughput, and flexible drive support. Also sold as the PERC H965i, this RAID card supports SAS, SATA and NVMe drives and leverages PCI-Express 4.0 to deliver exceptional I/O performance while the 8GB DDR4 cache and PERC12 firmware ensure consistent, low-latency operation for mixed workloads.

Key Specifications & Identifiers

• Manufacturer: Dell
• Part Number / SKU: W2C1K
• Product Type: RAID controller / storage array controller
• Sub-Type: PERC (PowerEdge Embedded RAID Controller)
• Device Form: Front — internal storage controller
• Host Interface: PCI-Express 4.0 (16-lane)
• Cache: 8GB DDR4 3200MT/s
• Implementation: PERC12 FRONT (onboard implementation)
• Drive Support: SAS, SATA, NVMe
• Maximum Interface Speed: 16 Gbps per lane (backplane dependent)
• Supported RAID Levels: RAID 0, 1, 5, 6, 10, 50, 60

Performance Highlights

• PCIe 4.0 bandwidth: Increased host throughput for heavy I/O applications and fast NVMe caching.
• Large DDR4 cache: 8GB on-board memory improves write coalescing and read acceleration for database, virtualization, and mixed transactional workloads.
• Multi-protocol drive compatibility: Native support for SAS, SATA and NVMe drive types enables hybrid storage topologies and flexible upgrade paths.

Supported RAID Configurations

The controller supports a wide range of array topologies to meet different availability and performance needs:

• RAID 0 — Striped arrays for maximum performance (no redundancy).
• RAID 1 — Mirroring for simple, fast redundancy.
• RAID 5 — Parity-based protection with efficiency for mixed read/write workloads.
• RAID 6 — Dual parity for high fault tolerance in larger arrays.
• RAID 10 — Mirror of stripes for both performance and redundancy.
• RAID 50 / RAID 60 — Striped sets of RAID 5/6 for scale and resilience across many drives.

Dell W2C1K PERC H965i RAID Controller — enterprise-grade storage performance

The Dell W2C1K PERC H965i Front Internal RAID Controller, commonly referred to as the PERC H965i, represents a modern, high-throughput storage controller designed for data centers, virtualization hosts, and high-performance storage arrays that require reliable handling of mixed SAS, SATA, and NVMe media. Built around a 16-lane PCIe 4.0 interface, the controller delivers the bus bandwidth necessary to saturate contemporary NVMe and SAS SSDs while maintaining backward compatibility with high-capacity rotational drives. The PERC H965i supports front internal connectivity, enabling direct connection to hot-swap drive bays and backplanes commonly found in Dell PowerEdge platforms. With 8GB of onboard cache and hardware-assisted RAID capabilities, the Dell W2C1K PERC H965i is positioned as a robust solution for I/O-intensive workloads, database servers, and software-defined storage infrastructures that demand consistent low latency and predictable throughput.

Performance characteristics and PCIe 4.0 advantages

The PERC H965i exploits the increased lane bandwidth of PCIe 4.0 to elevate throughput and reduce bottlenecks in multi-drive configurations. The 16 lanes of PCIe 4.0 provide a high-bandwidth conduit between the host CPU and the RAID controller, which is critical when aggregating multiple NVMe devices or large numbers of SAS SSDs. Applications that benefit from the Dell W2C1K PERC H965i's bandwidth include transactional databases, virtualization hypervisors, real-time analytics engines, and content delivery nodes. The 16-lane PCIe 4.0 architecture ensures that sustained sequential reads and writes, random I/O operations, and mixed workload patterns can achieve high IOPS while maintaining low queuing delay. Combining PCIe 4.0 with hardware offload for parity calculation and RAID rebuilding minimizes CPU overhead and accelerates rebuild times, thereby improving availability and overall system responsiveness under degraded conditions.

Mixed media support: SAS, SATA, and NVMe compatibility

One of the defining features of the Dell PERC H965i is its ability to support a heterogeneous mix of storage media. By accommodating SAS, SATA, and NVMe drives, the controller provides system architects with the flexibility to design tiered storage architectures within the same server enclosure. NVMe devices deliver ultra-low latency and very high IOPS suitable for hot data sets, while SAS and SATA SSDs offer cost-effective performance and large-capacity options for warm and cold tiers. The Dell W2C1K PERC H965i's firmware and connector topology are engineered to manage drive discovery, zone mapping, and path management across these interfaces, ensuring that mixed-media deployments operate reliably and predictably. For system builders, this means the ability to place the hottest workloads on NVMe drives connected through the controller's high-throughput paths while still leveraging large-capacity SAS arrays for archival or bulk storage without needing separate controllers for each media type.

Cache architecture and data protection

Onboard cache plays a pivotal role in modern RAID controllers, and the PERC H965i includes 8GB of cache designed to accelerate write coalescing, read-ahead prefetching, and metadata operations. This cache size is engineered to strike a balance between cost, endurance, and performance for enterprise workloads. The controller's cache subsystem includes techniques to protect cached data during power loss events, such as integrated power-loss protection mechanisms or support for external supercapacitor or battery modules in compatible server configurations. Data integrity features such as end-to-end CRC checks, atomic write handling, and advanced error checking reduce the risk of silent data corruption and ensure that RAID parity calculations remain consistent. The Dell W2C1K PERC H965i's caching algorithms also enhance small random write performance, which is especially beneficial for virtual machine disk images, mail servers, and OLTP databases that generate many small synchronous writes.

RAID levels, rebuild behavior, and availability

The PERC H965i supports a comprehensive set of RAID levels to meet diverse availability and performance requirements. Hardware-accelerated RAID 0, 1, 5, 6, 10, and other nested configurations enable administrators to choose the appropriate tradeoff between redundancy and usable capacity. RAID 6 support is vital for large-capacity arrays where the probability of an unrecoverable read error during rebuild is non-negligible; dual-parity protection helps prevent data loss while drives are being reconstructed. The controller's rebuild engine optimizes background rebuilds to minimize the performance impact on active workloads while completing the rebuild in an efficient manner. Features such as background consistency checks, rapid array expansion, and patrol reads further contribute to long-term data integrity and reduce the administrative burden associated with array maintenance. For mission-critical environments, the Dell W2C1K PERC H965i gives IT teams predictable availability characteristics and the tools needed to restore degraded arrays quickly and safely.