Web-Server, File-Server and Workstation Patterns

The disk arrays are tested under loads typical of servers and workstations. The names of the patterns are self-explanatory. The Workstation pattern is used with the full capacity of the array as well as with a 32GB partition. The queue depth is limited to 32 requests in the Workstation pattern.

We will be discussing diagrams but you can click the following links for the detailed results and performance ratings:

• IOMeter: File-Server
• IOMeter: Web-Server
• IOMeter: Workstation
• IOMeter: Workstation, 32GB

There is no point in discussing the Web-Server diagrams individually because the numbers change but the standings do not. So, our comments will refer to the behavior of every type of the array under this reads-only load.

The Western Digital RE3 is obviously the best at long queue depths. The two new drives from Seagate share second place and challenge the leader at short queue depths. The Western Digital RE2 stands out among the lower-density disks, and the Hitachi is good, too. The Seagate 7200.10 is the worst drive here (its enterprise counterpart is much better), but the Samsung is poor as well. We should keep it in mind, however, that the Samsung has the same specs but slowed-down heads.

There are differences in the File-Server pattern due to the presence of write requests. Therefore we will discuss the diagrams separately.

Quite expectedly, the Western Digital RE3 and the Seagate Barracuda 7200.11 take first and second places when working in RAID0 (and, running a little ahead, in the other types of the array). It is not so clear with third place. Due to the performance fluctuations we have seen in the Database pattern the Seagate ES.2 is not always third but loses occasionally to the lower-density and older Western Digital RE2. This serves to demonstrate that firmware algorithms are very important. The next contesting pair is the Hitachi and the Seagate ES. The former is better at low loads and the latter, at high loads. Last place goes to the Seagate 7200.10 although the Samsung is almost as slow as it at long queue depths.

The overall picture with the RAID10 arrays is roughly the same as with the RAID0 arrays but the Seagate ES.2 is now confidently third.

When it comes to RAID5, there is some fighting again with the same participants. Like in our previous reviews, the Hitachi expresses its dislike of this type of the array and joins the group of losers. The Samsung struggles with RAID5, too. It is the overall worst drive in this subtest.

The Seagate 7200.11 catches up with the Western Digital RE3 in RAID0 under Workstation load. Thus, they share top place here. This combination of load and array type seems to be difficult for Western Digital’s products: the RE2 is rather slow at medium queue depths, so the Seagate ES.2 easily makes to the top three.

The Samsung is poor at short queue depths whereas the Seagate 7200.10 is last at long queue depths.

When we switch to RAID10, the RE3 is in the lead again while the RE2 beats the ES.2 at short queue depths. There are no changes among the losers: the Samsung is poor at short queue depths and the Barracuda 7200.10 is in last place at long queue depths.

The leaders do not change with RAID5. The Samsung and the Hitachi show their dislike of this array type at short and long queue depths, respectively.

When the test zone is limited to a 32-gigabyte partition, the standings change considerably. For example, we’ve got four drives fighting for top place in RAID0: the Western Digital RE3 and the Seagate 7200.11 are now challenged by the Seagate ES.2 and the Hitachi. The latter has found a suitable subtest at last! The Samsung now competes with the Western Digital RE2 and Seagate ES at short and long queue depths, respectively. The Seagate 7200.10 is left alone in its miserable last position.

Take note of the behavior of Western Digital’s products. They feel much better than their opponents at very long queue depths, delivering a nice performance boost then.

The RE3 regains its leadership in RAID10. Then, the Hitachi and the RE2 go neck and neck with Seagate’s two new models at short queue depths. Their higher recording density doesn’t help at all here. It is only at a much longer queue depth that the Hitachi and ES.2 (yes, the ES.2 rather than the lower-density RE2) fall behind the two others, the ES.2 being the worst drive among the four.

Western Digital’s products feel at ease in RAID5 when the test zone is limited: the RE3 is unrivalled. The RE2 competes with the new drives from Seagate and beats them at medium queue depths. Interestingly, the Hitachi is not so bad with this array type now. It is the Samsung and the 7200.10 that are the slowest drives here.