Performance in Intel IOMeter File Server & Web Server Petterns

These patterns simulate the operation of the disk subsystem of a typical file- or Web-server. First goes the File Server pattern, in write-through and write-back modes:

The following graphs show the dependence of the performance on the request queue depth:

The RAID0 arrays are highly scalable. The RAID1 and RAID10 are always faster than the single drive and the two-disk RAID0, respectively. The speeds of the RAID5 arrays are the same, like in the previous tests.

On enabling WB caching, nearly all the arrays speed up. The speeds of the three- and four-disk RAID5s are different now, unlike in the write-through mode.

We calculate the performance rating for each array by averaging the controller speed under each workload. This allows comparing the arrays:

The four-disk RAID0 took the first place in performance, but only because the File Server pattern has 20% of writes, which RAID0 performs faster than RAID10. RAID1 fell behind the two-disk RAID0 in the write-through mode, but outperformed it in the write-back mode. RAID5 arrays of two and three disks swap their places in different caching modes.