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Hitachi Deskstar 7K400 and 7K250 HDD


Acoustic noise and power consumption

We shall review the acoustic properties of these hard disks in more detail in another article. And here I want to note that both five-platter Hitachi Deskstar 7K400 hard disks are subjectively almost the noisiest ones among modern desktop disks. And while the rotational noise (clanging and rumbling) due to liquid dynamic bearing is not that noticeable (though subjectively it's more prominent than in 7K250 series hard disks), the rattling heads in active seek mode leave no doubts that something is actively operating near you. :) Frankly speaking, I don't see any point in having this hard disk in your room, while there are quieter solutions. Though it won't be very disturbing in quiet seek mode even at night.

What concerns power consumption and heat dissipation, you can see these characteristics of 7K400 series hard disks in their specifications in the beginning of the article. Seemingly horrible at first sight (over 10 W in operation mode!), they turned out rather mild: fixed in the metal chassis of the PC case (without any additional cooling or air flow), the 7K400 series hard disks have never overheated to a dangerous level for the six days of active testing — their temperature was fluctuating between 42 and 50 degrees Centigrade, and it was lower than in some desktop hard disks from other manufacturers. So the real power consumption of these hard disks is probably noticeably lower than claimed in their specifications.


Thus, Hitachi Deskstar 7K400 hard disks have achieved a new capacity record among 3.5-inch desktop storage devices (400 GB) using a long forgotten configuration with five platters and ten heads. Now a 1U-format data storage device can hold up to 1.6 terabyte of data instead of 1 terabyte for the previous generation of Deskstar drives. I would also like to award Hitachi Deskstar 7K400 hard disks with our editors' "Original design" award.

But was the game worth the candle? From the point of view of a home or office user — I doubt it very much! 7K400 series (Kurofune) hard disks turned out a tad slower in performance than their direct predecessors and forefathers — Deskstar 7K250 series hard disks (Vancouver 3), though they use practically the same components! The new hard disks are also worse in their noise level, power consumption, and shock resistance than the old models. The capacity of a single disk is not surpassed yet (so far). But these days only the "laziest" chipset does not have a RAID-controller, so it's no problem to combine two 200 GB or even 300 GB hard disks into a stripe and to obtain 400-600 GB and approximately 1.5 times (or even two times) as high performance as in Kurofune (literally — two 200 GB models will cost approximately as one Kurofune)! I could have published performance results of a simple RAID-array of two 200 GB hard disks, but the review would have been devoted to absolutely different issues then. ;) Believe me, this RAID of two modern ATA hard disks will have practically the same noise level as one Kurofune. What concerns power consumption — is it that important for a desktop?

So the new Hitachi giants of desktop hard disks are designed for: (1) those users, for whom the word "cool" is very important, and (2) professional purposes, which Hitachi stresses in connection with these models: not for traditional high-performance and gaming PCs and workstations, but rather for NearLine Storage (disk-to disk backups, archive and constant content storage, data loss prevention and data restoration), as well as for digital video recorders, home media-servers, and video editing and storage devices. These 7K400 series hard disks "specialize" in such streaming (including audio and video) utilizations (ATA-7, new firmware algorithms, and all that). However, according to our tests, these Hitachi optimizations provide no special advantages in this class of tasks so far. We are looking forward to the new series of desktop hard disks from this manufacturer, which are soon to be expected.

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

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