Performance in IOMark

We use our internal IOMark tool for low-level tests. Let’s check out the sequential read speed of the drives first.

• Data-transfer graph for Hitachi Deskstar 7K1000
• Data-transfer graph for Hitachi Deskstar 7K1000.B
• Data-transfer graph for Hitachi Deskstar E7K1000
• Data-transfer graph for Samsung SpinPoint F1 DT
• Data-transfer graph for Samsung SpinPoint F1 RAID
• Data-transfer graph for Seagate Barracuda 7200.11 (4 platters)
• Data-transfer graph for Seagate Barracuda 7200.11 (3 platters)
• Data-transfer graph for Seagate Barracuda SV35.3
• Data-transfer graph for Western Digital Caviar Green (4 platters, 16 MB)
• Data-transfer graph for Western Digital Caviar Green (3 platters, 16 MB)
• Data-transfer graph for Western Digital Caviar Green (3 platters, 32 MB)
• Data-transfer graph for Western Digital RE2-GP
• Data-transfer graph for Western Digital RE3
• Data-transfer graph for Western Digital Caviar Black

Now we can compare the HDDs by the read speed at the beginning and end of the partitions created on them.

There is one preliminary comment about this test: with modern adaptive formatting of platters, the speed at the beginning of the disk (i.e. the maximum speed) depends greatly on whether the disk has a lucky combination of a head and platter surface there. If there is a lucky pair, the speed is excellent. If there are two or more lucky pairs, there will be more peaks of speed and the graph will be smoother. As a matter of fact, the HDDs have very different pairs that vary in speed up to 10MBps, and even up to 15MBps with the Samsung F1 DT. As a result, our tool reports the latter’s top speed wrongly, showing a lower value.

Let’s now see what the numbers have to tell us.

First, we can see the effect of higher recording density: the 4-platter WD Caviar Green drives with a spindle rotation speed of 5400rpm are as fast as the 5-platter Hitachi. The 3-platter Green models are competitive to the 4-platter drives from Seagate, the best of them (in terms of head/surface pairs) even reach the speed of the worst of 7200rpm 3-platter drives (it is the Samsung F1 DT due to its unlucky head/surface pairs). This effect is especially conspicuous with the two WD10EACS models: the name is the same but the speed differs by 15MBps.

Then, it is good that the 3-platter 7200rpm models all are faster than 100MBps. Seagate’s drives have always had very good sequential speeds and now notch 120MBps in the 3-platter design. And if you take a look at the graph, you can see that this speed is achieved not on one particular head/surface pair, but on all pairs. Hitachi’s 3-platter drives can be commended for good results, too. The 7K1000.B and E7K1000 have the best speed at the end of the partition. They also have good speed at the beginning and smooth graphs, thus showing very stable overall performance.

And what about buffer memory?

• Buffer speed for Hitachi Deskstar 7K1000
• Buffer speed for Hitachi Deskstar 7K1000.B
• Buffer speed for Hitachi Deskstar E7K1000
• Buffer speed for Samsung SpinPoint F1 DT
• Buffer speed for Samsung SpinPoint F1 RAID
• Buffer speed for Seagate Barracuda 7200.11 (4 platters)
• Buffer speed for Seagate Barracuda 7200.11 (3 platters)
• Buffer speed for Seagate Barracuda SV35.3
• Buffer speed for Western Digital Caviar Green (4 platters, 16 MB)
• Buffer speed for Western Digital Caviar Green (3 platters, 16 MB)
• Buffer speed for Western Digital Caviar Green (3 platters, 32 MB)
• Buffer speed for Western Digital RE2-GP
• Buffer speed for Western Digital RE3
• Buffer speed for Western Digital Caviar Black

The maximum speed of working with the buffer data depends directly on the HDD’s processor which is responsible for data transfers over the interface and on the speed of buffer memory proper (the controller the HDD is attached to influences this speed too, but we connect all the drives to the same controller in this test). Thus, this test helps compare the HDDs’ electronics.

It is clear that HDD generations share the same electronics. WD’s 4-platter Green models from both desktop and enterprise series are the worst in terms of electronics – the developer must have tried to reduce power consumption too much when designing them. Hitachi’s 5-platter model is not much faster: its result must be influenced by the “time-tested” design it has inherited from the previous series. Western Digital’s 3-platter drives obviously have new electronics and have become faster, but not fast enough to catch up with the HDDs from Samsung and Seagate. Hitachi’s new series are in the lead thanks to the new LSI-Infineon controllers – they boast a data-transfer rate of 250MBps when reading data from the buffer.

The graphs are both interesting and not. On one hand, you can easily name the manufacturer of the particular drive without seeing its name. On the other hand, you want some progress and variegation. Samsung’s and Hitachi’s products have the smoothest graphs of reading and writing. The old 5-platter Hitachi has minor problems with writing large data blocks but the company’s new models deliver almost perfectly flat graphs (we wonder if the new processor is equipped with a larger input buffer). WD’s six models all behave in the same way here, producing excellent read graphs but having some fluctuations of speed at writing. Seagate’s drives are traditionally disappointing. Their read and write speeds drop by 25% and 50%, respectively, at data blocks larger than 256KB. We wish Seagate followed Hitachi’s example.