2  Data Transfer Rate 2.1  Introduction Data transfer measurements were made using an IBM eServer pSeries 620 processor connected to an IBM Ultrium 2 tape drive, in three different configurations. First an IBM Ultrium 2 tape drive with an Ultra3 SCSI  port was connected to the Ultra 3 SCSI port on the processor. Second, an IBM Ultrium 2 tape drive with a 2 Gigabit Fibre channel port was connected to a 2 Gigabit Fibre channel port on the processor. And third, an IBM Ultrium 2 tape drive with a 2 Gigabit Fibre channel port was connected to a 1 Gigabit Fibre channel port on the processor. Tests were executed using a program that writes data from memory with four different data patterns. The four patterns had differing compressibility characteristics.  The program analyzed back the throughput as a function of the amount of data written divided by the time it took for the operation to complete.  The program took the measurements between wraps, removing any performance boosts at the beginning when the data buffer is being filled.  The purpose of these measurements is to show how the tape drive performs when streaming data.  (All data rates are reported in terms of Mega Bytes per seconds (MB/sec) where a Mega Byte is 1,000,000 bytes.) 2.2  Test Environment The  test environment was composed of the following hardware: 8.1.6.0 Atape Level: FC 6228: 2 Gigabit Fibre Channel Adapter (Type 4-W) Placement:  64 bit 3.3V Slot at 66 MHz Fibre Adapter: FC 6227: Gigabit Fibre Channel Adapter (Type 4-S) Placement:  64 bit 3.3V Slot at 66 MHz Fibre Adapter: FC 6203: Dual-Channel Ultra3 SCSI (Type 4-Y) Placement:  64 bit 3.3V Slot at 66 MHz SCSI Adapter: AIX 5.2.0.0 Operating System: eServer pSeries 620 (Machine type 7025 - 6F1) Processor: Page 4 of 10 p1   p2   p3   p4   p5   p6   p7   p8   p9   p10