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Hitachi Deskstar 7K400 and 7K250 HDD

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Performance in applications

Now let's see how the pros and cons of the hard disk design noted above reveal themselves in applications. At first, let's find out how well the hard disks are optimized for multithreaded operations. For this purpose I traditionally use NBench 2.4 tests, where 100 MB files are written to disk and read from it in several simultaneous threads (in this case we use FAT32, though this test demonstrates similar results on NTFS).

This diagram lets us evaluate the efficiency of multi-threaded lazy write procedures of the hard disks in real (not synthetic, as on the diagram with the average access time) conditions when the operating system works with files. Actually, the picture is similar for all Hitachi hard disks: all of them (but a tad worse than some competitors) cache well data for multithreaded writing, even if writing threads are spaced wide apart within the hard disk and they lose not more than half of their data rate on the average. The old 180GXP has suddenly become a winner by the total points taken (which correlates with the results of ATTO test on average files), the silver medal is shared by the 7K400 UATA and 7K250 SATA models. They slightly outscored the 7K400 SATA model, which is practically equally fast in quiet and noisy seek modes. And the last place (though still not lagging far behind) is taken by the hard disk with 2 MB buffer.

The situation is different in multi-threaded reading: all Hitachi hard disks lose more than half of their data rate already with two closely spaced threads. And when the two threads are wide apart, the data rate drops almost by ten times! Both 7K400 models are leading in this test, their performance losses at "quiet seek" being about 10%. On the whole, multi-threaded reading cannot be considered the strong point of Hitachi hard disks, though these disks are good at caching data for reading single files of the average size (judging from the ATTO test and some other).

Now let's see how these hard disks fair in the elderly but still popular Disk WinMark 99 test from the famous WinBench 99 package. We carry out these tests not only "for the beginning" but also for "the center" (by capacity) of the storage medium for both file systems.

All Disk WinMark 99 tests have the same outsiders both in Business and High-End performance — the 7K250 hard disk with 2 MB buffer is always the last, losing from 15% to 33% to the leaders in performance; and the last but one is the senior model in the 180GXP series, which is not that much outscored by the leaders — 10% on the average (from 5% to 13%).

Senior SATA hard disk of the 7K250 series is the absolute leader. It has won in seven out of eight tests — the best seek time and average platter data rate make themselves felt. This hard disk is closely followed by the 7K400 UATA model, which outscored its SATA counterpart in five tests out of eight: as you can see, faster interface is not of much help, though it's the fault of additional latency because of the interface translator in the SATA model. What concerns the quiet seek mode in the 7K400 model, in these tests it does not deteriorate the performance but even improves it in half of the cases. However, these improvements are so small that they are within the test error limits.

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Alex Karabuto (lx@ixbt.com)
January 18, 2005


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