Product manual

77 A1 69UP Rev00 4-1
4. Performance Features
CDA 7 offers improved performance over conventional Storage Control Units and
disk device designs. The CDA 7 features described below allow high cache hit
ratios and less processing overhead, reducing response time and improving
throughput.
4.1 Cache
A cache size of up to 8,192 MB and intelligent caching algorithms greatly improve
hit ratios and overall subsystem response time. CDA 7 caches all read and write
operations making them transparent to the host operating system.
4.2 Multiple Channel Directors
CDA 7 contains multiple channel directors, Ultra SCSI or fibre channel type, each
supplying an independent path to cache or disk from the host system. The
CDA 7 has two or four channel directors.
Each Ultra SCSI director supports up to four SCSI channels.
Each fibre channel director supports two Fibre channel ports.
4.3 Parallel Processing
Each channel director and disk director has two resident microprocessors, and each
disk device has one resident microprocessor. These microprocessors make use of
advances in parallel processing to reduce processing time and improve throughput.