HP P3410A HP NetRAID 1M/2M Installation & Configuration - Page 12

Chapter 1 Introduction Adapter Hardware and Battery-backed Cache IOP: The I/O processor (IOP) directs all functions of the adapter, including command processing, PCI and SCSI bus transfers, RAID processing, drive rebuilding, cache management, and error recovery. • The IOP for the HP NetRAID-1M adapter is the Intel i960RM® Intelligent I/O RISC processor running at 100 MHz. • The IOP for the HP NetRAID-2M adapter is the Intel i960RN® Intelligent I/O RISC processor running at 100 MHz. The HP NetRAID-1M adapter has a 32-bit, 33 MHz PCI Bus Interface. The HP NetRAID-2M adapter has a 64-bit, 66 MHz PCI Bus Interface. Cache: All HP NetRAID-1M and 2M adapters have cache memory. • For the HP NetRAID-1M adapter, cache memory resides in a 32-MB SDRAM DIMM with ECC. • For the HP NetRAID-2M adapter, cache memory resides in a 64-MB or 128-MB SDRAM DIMM with ECC, depending on the model purchased. The HP NetRAID-1M or 2M adapters support Direct and Cached I/O and Write Through or Write Back caching, which can be selected for each logical drive. To improve performance in sequential disk accesses, the HP NetRAID-1M and 2M adapters use Adaptive Read Ahead caching by default, but it can be disabled to Normal or set to simple Read Ahead caching. Battery: Battery backup of the cache is standard for the HP NetRAID-2M adapter. It is not available with the HP NetRAID-1M. Alarm: A tone generator on the HP NetRAID-1M and 2M adapters provides audible warnings (alarms) when RAID system errors occur. 4