Hitachi Travelstar Z5K320 320GB 7mm 2.5-inch Hard Drive

With only a handful of 7mm drives on the market, Hitachi aims high and low. Today we look at the budget end of the market with the 5,400 RPM Z5K320.

Manufacturer: Hitachi
8 minutes & 27 seconds read time


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Last January at CES I was introduced to a new form factor of 2.5" drives. Seagate was developing the drive for an ASUS netbook, but promised the 7mm height would be adapted by other netbook makers before the end of the year. Seagate's Momentus Thin wasn't the first 7mm drive I had worked with, the Intel SSD products were also this same height, but Seagate was the first to shine a spotlight on these amazingly thin drives.

Hitachi didn't wait to see how this market would develop and went straight into action making their first 7mm thin HDDs, the Z-Series. The Z-Series can be broken down to two categories; the Z5 and Z7. These are the 5,400 and 7,200 RPM drives and as you would expect the 5 and 7 in the names make differentiating them apart much easier.

Today we are going to look at the Z5, 5,400 RPM Series drive that matches Seagate's Momentus Thin in platter speeds, but offers more options when it comes to storage capacity.

Let's take a look at the specifications and see what sizes Hitachi offers the Z5 in.

Specifications, Pricing and Availability

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The biggest selling point of this drive is obviously the height, 7mm. Until now the standard has been 9.5mm for notebooks. In the enterprise market there are also 2.5" form factor drives that are 12 and 15mm thick, but most of those have been SAS drives and not compatible with notebook drives 5v power requirements. The 7mm standard is backwards compatible with 9.5mm thick drives, but is being positioned to take over the low cost segment of the market.

With a reduced size all current 7mm drives are limited to a single platter. This is an area where Hitachi is currently leading the competition since Seagate's highest capacity 7mm thick drive is only 250GB. Hitachi's new Z Series comes in 160, 250 and 320GB capacity sizes.

The Z Series is divided into two main categories; Z5 the 5,400 RPM models and Z7 for 7,200 RPM drives. Today we are going to focus on the Z5K320, a 320GB drive that has an 8MB cache buffer and a very low acoustic rating.

After a quick search I was unable to find the Hitachi Z5K320 at Newegg, but Provantage had stock available for 50.72 USD at the time of writing. For comparison we found Seagate's 250GB 7mm drive online for 60 USD at This puts Hitachi's Z5K320 in a nice position since it has higher capacity and costs less than the main competition.

The Hitachi Z5K320 320GB HDD

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As far as drives go the Z5K320 looks like all of the others from the front and back. The top label has all of the information you would expect it to have; model and serial number, power draw, all of it is listed on the label.

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Modern drives place all of the surface mount components on the PCB towards the drive, so there isn't much to see on this side.

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The side is where things get interesting. The drive on the bottom is a Hitachi 7K500, a typical 9.5mm drive. This is what you have come to know as a "standard" notebook drive. The drive on top is our Z5K320, the 7mm drive in a format that we can now call a standard as well.

Even though the Z5K320 is only 7mm's tall, it still conforms to the specifications making it capable of being installed where 9.5mm drives reside now. With netbooks quickly adapting the new 7mm standard and 9.5mm drives being too thick, we are going to see a lot more of these single platter drives hit the market since they are cheaper to build and allow netbook manufacturers to make thinner devices.

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Looking at the back of the drive, we see the Z5K320 uses standard SATA power and data connections.

Test System Setup and ATTO Baseline Performance

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We would like to thank the following companies for supplying and supporting us with our test system hardware and equipment: AVADirect, GIGABYTE, Cooler Master, LSI and Noctua.

You can read more about TweakTown's Storage Product Testing Workstation and the procedures followed to test products in this article.

Without Seagate's Momentus Thin on hand we won't be able to put the two head to head like I would have liked. To be honest, I never really thought I would be testing a low cost drive quite like the Z5K320.

ATTO Baseline Performance

Version and / or Patch Used: 2.34

ATTO is used by many disk manufacturers to determine the read and write speeds that will be presented to customers.

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The Hitachi Z5K320 delivers amazing raw performance in ATTO and is only around 10MB/s down from the Hitachi 7,200 RPM 2.5" notebooks drive.

Benchmarks - HD Tune Pro

HD Tune Pro

Version and / or Patch Used: 4.00
Developer Homepage:
Product Homepage:

HD Tune is a Hard Disk utility which has the following functions:

- Benchmark: measures the performance
- Info: shows detailed information
- Health: checks the health status by using SMART
- Error Scan: scans the surface for errors
- Temperature display

HD Tune Pro gives us accurate read, write and access time results and for the last couple of years has been gaining popularity amongst reviewers. It is now considered a must have application for storage device testing.

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Despite its single platter design the Hitachi Z5K320 holds itself quite well against the higher priced competition that we paired it with for this review. The only other 5,400 drive in this round-up style result list is the Western Digital Scorpio Blue.

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Just like the Read test, the Z5K320 just didn't have enough to match the higher spec drives, but it did run very close to despite its single platter disadvantage.

Benchmarks - Everest Random Access Time

Everest Random Access Time

Version and / or Patch Used: 4.60
Developer Homepage:
Product Homepage:

Everest Ultimate and Corporate Edition offer several different benchmarks for testing and optimizing your system or network. The Random Access test is one of very few if not only that will measure hard drives random access times in hundredths of milliseconds as oppose to tens of milliseconds.

Drives with only one or two tests displayed in write the write test mean that they have failed the test and their Maximum and possibly their Average Scores were very high after the cached fills. This usually happens only with controllers manufactured by JMicron.

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The Z5K320 was able to beat the WD Scorpio Blue in the average read access test and is very close to the performance of the 7,200 RPM drives.

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The Western Digital Scorpio Blue had an issue with the write access test most likely due to its advanced format configuration. With the WD data not available we turn to the other drives and this is where things start to get interesting. Hitachi's Z5K320 actually scored better than the 7K500, a 7,200 RPM drive.

Benchmarks - PCMark Vantage Hard Disk Tests

PCMark Vantage - Hard Disk Tests

Version and / or Patch Used: 1.0.0
Developer Homepage:
Product Homepage:
Buy It Here

PCMark Vantage is the first objective hardware performance benchmark for PCs running 32 and 64 bit versions of Microsoft Windows Vista. PCMark Vantage is perfectly suited for benchmarking any type of Microsoft Windows Vista PC from multimedia home entertainment systems and laptops to dedicated workstations and high-end gaming rigs. Regardless of whether the benchmarker is an artist or an IT Professional, PCMark Vantage shows the user where their system soars or falls flat, and how to get the most performance possible out of their hardware. PCMark Vantage is easy enough for even the most casual enthusiast to use yet supports in-depth, professional industry grade testing.

FutureMark has developed a good set of hard disk tests for their PCMark Vantage Suite. Windows users can count on Vantage to show them how a drive will perform in normal day to day usage scenarios. For most users these are the tests that matter since many of the old hat ways to measure performance have become ineffective to measure true Windows performance.

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HDD1 - Windows Defender
HDD2 - Gaming
HDD3 - Windows Photo Gallery
HDD4 - Vista Startup
HDD5 - Windows Movie Maker
HDD6 - Windows Media Center
HDD7 - Windows Media Player
HDD8 - Application Loading

For most users these tests have the most meaning since they are what Windows uses every day. The Hitachi Z5K320 performed very well when compared to the Western Digital drive.

Benchmarks - AS SSD

AS SSD Benchmark

Version and / or Patch Used: 1.2.3577.40358
Developer Homepage: Alex Intelligent Software
Product Homepage: Alex Intelligent Software
Download here:

AS SSD determines the performance of Solid State Drives (SSD). The tool contains four synthetic as well as three practice tests. The synthetic tests are to determine the sequential and random read and write performance of the SSD. These tests are carried out without the use of the operating system caches.

In all synthetic tests the test file size is 1GB. AS can also determine the access time of the SSD, the access of which the drive is determined to read through the entire capacity of the SSD (Full Stroke). The write access test is only to be met with a 1 GB big test file. At the end of the tests three values for the read and write as well as the overall performance will be issued. In addition to the calculated values which are shown in MB/s, they are also represented in IO per seconds (IOPS).

Note: AS SSD is a great benchmark for many tests, but since Crystal Disk Mark covers a broader range of 4K tests and HD Tune Pro covering sequential speeds, we will only use the Copy Benchmark from AS SSD.

- Copy Benchmark

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Most netbook users don't keep a large amount of media on their netbook, but with Hitachi raising the capacity limits that will soon change. With media and other extra data users will want to transfer that data to and from the drive and these are the tests that show how well that happens. Given the design, I would say the Z5K320 faired pretty well.

Benchmarks - Passmark

Passmark Advanced Multi-User Tests

Version and / or Patch Used: 6.1
Developer Homepage:
Test Homepage:

Many users complain that I/O Meter is too complicated of a benchmark to replicate results so my quest to find an alternative was started. Passmark has added several multi-user tests that measure a hard drives ability to operate in a multi-user environment.

The tests use different settings to mimic basic multi-user operations as they would play out on your server. Variances is read / write percentage as well as random / sequential reads are common in certain applications, Web Servers read nearly 100% of the time while Database Servers write a small amount of data.

The Workstation test is the only single user environment and will be similar to how you use your system at home.

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The Hitachi Z5K320 is about as far from a server drive as you can get, but it is still fun to run these tests to see how these notebook drives fair. I was a bit surprised to see the Z5K320 perform so well when put against the Scorpio Blue.

Final Thoughts

The 7mm market is still in its infancy. When you put it on a timeline the 7mm category is actually newer than solid state drives. The underlying technology behind these 7mm drives is tried and true, a traditional HDD in its simplest form. Hitachi has hit the ground running and isn't standing still with just one offering in this new category, which is good for consumers looking for a way to speed up their netbooks.

With that said, Netbook users aren't the only ones to benefit from the new 7mm form factor. The drives are being sold at very low prices so anyone with a need for more storage at a low cost can get in the action as well. Looking back, I wish I would have taken a closer look at Seagate's Momentus Thin when I had the opportunity so I would have performance data on hand for this article.

As it sits now, Hitachi is the one company offering a 7mm drive that is larger than 250GB. If you are more worried about performance rather than capacity, Hitachi is also the only company offering a 7,200 RPM 7mm drive as well and it also can be purchased with 320GB of storage capacity.

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