HP A7173A PCI-X Dual Channel Ultra320 SCSI Host Bus Adapter Performance White Paper for HP PA-RISC Servers

6
Scalability
The A7173A dual-channel Ultra320 SCSI adapter offers an impressive level of linear scalability for the
most intense SCSI storage systems. Using two A7173A dual-channel Ultra320 SCSI adapters in non-
shared PCI bus slots can dramatically increase your SCSI read-throughput to over 1000 MB/sec;
equivalent to approximately eighty-two percent of the Four-Bus U320 SCSI Theoretical Maximum.
Chart 4a shows the sequential-read throughput performance of multiple A7173A and A6829A
adapters installed in an HP rp4440 PA-RISC Server. The horizontal axis represents the number of utilized
SCSI buses, while the vertical axis represents the overall throughput in MB/sec.
Chart 4a: 256KB Sequential Read and Write Throughput
NOTE:
Each dual-channel SCSI adapter provides two SCSI buses with a maximum of 15-devices per bus.
0
200
400
600
800
1000
Thr oughput (M B/ sec)
U160 Write
130 249 382 494
U160 Read
135 259 384 514
U320 Write
233 361 587 697
U320 Read
264 505 763 1,000
1 Bu s 2 Bu se s 3 Bu se s 4 Buses