HP 504062-B21 Performance factors for HP ProLiant Serial Attached Storage (SAS - Page 12

Figure 8 compares the random read performance of 10K and 15K SFF SAS drives for arrays of three to eight drives, using RAID 5 with the block size set to 128 KB. Figure 8. Random read performance: 10K versus 15K RPM SFF SAS drives, RAID 5 2500 4 KB Random Read 64 KB Random Read 512 KB Random Read 2000 1500 IOPS 1000 500 No. of drives 3 4 5 6 7 8 3 4 5 6 7 8 3 4 5 6 7 8 10K HDD & P400 controller 15K HDD & 6402 controller As indicated in Figure 8, 15K drive arrays consistently provide higher random read IOPS than 10K drive arrays. Also, overall performance scales with array size (number of drives). Note that performance is best when retrieving data blocks that are larger than the RAID 5 stripe size (128 KB in this case). For optimum performance, the stripe size should be configured for the specific application. 12