The workload is getting heavier, and we see the arrays perform differently. The “mirrored” arrays (RAID1 and RAID10) are always faster than the single drive and the two-disk RAID0, respectively, save for the Random Write mode. The maximum difference in speed (in the Random Read mode) is 75%, which is close to the results of 3ware’s TwinStor technology. At the same time, their speeds diminish as the writes percentage grows (contrary to what we had under linear workload), because the number of requests is high enough under this workload for the controller’s optimized reading from the mirror to be more efficient than the optimization of write requests by the hard disk drives. The RAID0 arrays show excellent scalability depending on the number of disks per array across all the work modes. The higher workload didn’t affect the RAID5 arrays, however. They stubbornly perform exactly like one another, and we may note that the speed of the four-disk RAID5 array is normal (because it equals the speed of the four-disk RAID0 in the Random Read mode), while the speed of the three-disk RAID5 is abnormally high!

The workload of 256 requests doesn’t affect the ranking. The mirror arrays, RAID1 and RAID10, have twice the speed of the single drive and the two-disk RAID0, respectively, in the Random Read mode. Their advantage decreases at higher writes percentages to come to naught at the Random Write point. The graphs of the RAID0 and JBOD arrays are practically “parallel”. The speeds of the RAID5 arrays are smoothly declining as there appear more writes in the queue and seem to correspond to the speed of the four-disk RAID5.