
108 DS8800 Performance Monitoring and Tuning
Figure 4-5 Single rank RAID-level comparison for a 4 KB random workload with 100% reads
These numbers are not DS8000 specific, because they represent the limits that you can
expect from a simple set of eight physical disks that form a RAID array. As outlined in 2.4.5,
“SAS 2.5 inch drives compared to FC 3.5 inch drives” on page 39, you can expect slightly
higher maximum I/O rates with 2.5 inch small form factor (SFF) 146 GB 15k SAS drives as
used in DS8800 systems.
For small block random read workloads, there is no significant performance difference
between RAID 5, RAID 6, and RAID 10, as seen in Figure ...