HP ProLiant 4500 Disk Subsystem Performance and Scalability - Page 21

ECG025.0997 WHITE PAPER (cont.) ... In Figure 10, our tests show that if you require 24 Gigabytes of storage capacity the performance gain of 33% is in using twelve 2GB disks instead of six 4GB disks. With concurrency taking place by using multiple lower capacity drives (twelve 2GB drives), more requests are being processed; thus improving performance. However, consider the limitations of this configuration. By having twelve lower capacity drives, you are limiting the maximum disk capacity on that controller. Like Capacity Scaling (RAID 0 - 1 Controller) Server Throughput (Bytes/sec) 20,000,000 18,000,000 16,000,000 14,000,000 12,000,000 10,000,000 8,000,000 6,000,000 4,000,000 2,000,000 0 4 33% 12 x 2GB 6 x 4GB 3 x 9GB 8 16 20 24 28 32 36 40 44 48 52 56 57 Number of Clients Figure 10: Like Capacity Scaling in a RAID 0 Environment. Similar test results were found in our RAID 5 environment. Again, when scaling (or using more drives) in an environment, the like capacity test shows a 54% performance increase when using eight 2GB drives versus four 4GB drives, as shown in Figure 11. 21