IBM 71P8644 ServeRAID-7k Zero Channel Ultra 320 SCSI Controller

ServeRAID-7k Zero Channel Ultra 320 SCSI Controller

The IBM 71P8644 ServeRAID-7k is a plug-in card designed for PC platforms requiring hardware RAID via a PCI-X host interface. It targets administrators managing internal storage arrays who need battery-backed cache protection without consuming an external SCSI channel. The Ultra320 controller integrates directly into the server backplane for simplified cabling.

Sustained load behaviour with battery-backed cache

Under continuous write workloads the onboard battery backup preserves cached data during unexpected power loss, preventing array corruption. The Ultra320 interface maintains a 320 MB/s maximum transfer rate across the bus, allowing the controller to sustain throughput during heavy I/O without relying on burst-only performance. RAID levels 0, 1, 5, 10 and 5EE distribute parity calculations to keep latency consistent.

Upgrades from software RAID or single-channel cards

This controller replaces host-based RAID implementations that consume CPU cycles and lack power-fail protection. It also supersedes single-channel SCSI adapters by providing zero-channel architecture for direct backplane connection. The jump is worthwhile when uptime and data integrity outweigh the cost of a dedicated hardware RAID engine.