Performance in Intel IOMeter WorkStation Pattern
The WorkStation pattern imitates intensive work of a user in various applications in the NTFS5 file system.
The situation is ordinary with the RAID0 arrays – the more disks the array has, the faster it processes requests. The speed of RAID1 is close to the single drive, while RAID10 surpasses the three-disk RAID0 in a few cases only (frankly speaking, it outperforms the four-disk RAID0 too at request queue = 4, but that’s a lucky exception). RAID5 arrays don’t show highest speeds and work slower than the single drive with single requests. This should come as no surprise since the WorkStation pattern has a lot of random write requests, which greatly reduce the speed of RAID5.
We calculate the performance rating for the WorkStation pattern by the following formula:
Performance Rating = Total I/O (queue=1)/1 + Total I/O (queue=2)/2 + Total I/O (queue=4)/4 + Total I/O (queue=8)/8 + Total I/O (queue=16)/16 + Total I/O (queue=32)/32.
Random write requests made RAID5 arrays perform slower than the single drive, and the three-disk RAID5 even lost to RAID1. RAID0 arrays ranked up according to the number of their disks. The performance of RAID10 is lower than that of the three-disk RAID0 because of the numerous write requests, although it did quite well in some modes.
Let’s see the effects of lazy writing on the performance of the arrays in this pattern:
Without caching to the disks, the arrays rank up the same way, but perform 30-50% slower (depending on the array type).