6.4  Speed Matching Performance Results Figures 6.1 - 6.2 summarize performance statistics of IBM Ultrium 2 at various net host data rates.  The charts show the following statistics for the comparison of speed matching Enabled vs Disabled: y Throughput - MB/sec y Reposition Events Figure 6.1 shows the throughput improvement in MB/sec with speed matching enabled relative to speed matching disabled.  The statistics show that at each host data rate from 17-32 MB/sec, speed matching enabled improves throughput.  Data points from 1-16 and from 33-40 were removed for clarity.  At those data points, there is no difference between speed matching enabled vs disabled. At speeds below 17 MB/sec, the drive’s 64MB internal buffer masks the performance degradation of repositions.  At speeds greater than 32 MB/sec the drive is operating at its fastest possible speed (same speed as speed matching disabled). Figure 6.1:  Speed Matching Comparison- MB/sec 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 Host Data Rate MB/sec 15 20 25 30 35 Speed On Disabled Speed Matching Comparison Throughput Page 16 of 20 p1   p2   p3   p4   p5   p6   p7   p8   p9   p10   p11   p12
p13   p14   p15   p16   p17   p18   p19   p20