Comparison: Seagate and WD 5mm thick hard drives

Seagate and WD have both rolled out 5mm thick drives that they hope will appeal to tablet and notebook manufacturers looking to create slimmer, more storage-rich devices

Ultra slim hard drives have been released by both Seagate and WD this year in a bid to allow tablet and notebook manufacturers to create thinner products with more built-in storage space. Whether or not manufacturers harness these new drives to create exciting new form factors and designs remains to be seen. Nevertheless, we’ve tested Seagate’s and WD’s slim hard drive offerings in a bid to see what kind of performance such small mechanical form factors can provide.

Both Seagate’s Laptop Ultrathin HDD and WD’s UltraSlim are 5mm thick drives that have a single platter and a capacity of 500GB. On their own, they are an impressive example of mechanical component miniaturisation, but we think the Seagate is more impressive than the WD; this is mainly because the Seagate drive keeps a standard SATA interface, while the WD has a proprietary interface that requires the use of an adapter cable if it’s to be used in a device with a conventional interface.

The WD drive on the left requires an adapter cable, while the Seagate on the right has a standard SATA interface built in.
The WD drive on the left requires an adapter cable, while the Seagate on the right has a standard SATA interface built in.

However, while it means the Seagate drive can easily slot into existing product designs, laptop and tablet makers might prefer the smaller, single connector of the WD drive if it means that they can make a smaller motherboard for it. They’ll just have to throw out any hopes of compatibility with standard drives in the process. That won’t be an issue if the laptops and tablets they make are sealed units that can’t be serviced by an end user. WD supplied an adapter cable for its drive for our testing, and this wasn’t a good solution in our test laptop: it was hard to plug in (our laptop uses a side-accessible drive bay), and there was no room to house the cable properly within the drive bay.

When we first saw the Seagate Laptop Ultrathin HDD at Computex earlier this year, we had our doubts about it and other 5mm hard drives being useful in a tablet, mainly because it could exhibit vibration, heat and noise characteristics that would put the user off while holding the tablet. While we still can’t tell you for sure whether those things will be an issue in a tablet, we can say that when we tested both the Seagate and the WD drives in a typical notebook, vibrations and heat couldn’t be felt at all -- thanks to the roomy chassis of the notebook no doubt. We also didn’t get annoyed by any noises from the drives, although the WD was more audible than the Seagate during seeking, and reading and writing operations.

More than the effects of the drive on end users, Seagate said it also had to consider the effects of end users on the drive. Making the drive rigid so that it would be shock and vibration resistant was a top priority, and to this end the company had to use steel to reinforce the drive, though device manufacturers will also be tasked with designing enclosures that can properly support the drive. The platter inside the 5mm Seagate drive is also the same as the platter inside the 7mm drive that the company offers, so aerial density was not an issue. The company claims that it used basically the same mechanics for the 5mm drive as it did for its 7mm drive, albeit with some slight modifications so they could fit into the smaller enclosure.

Both drives are 5mm thick and designed to fit into slimline devices.
Both drives are 5mm thick and designed to fit into slimline devices.

As for performance, both drives put up similar numbers in our tests, but the Seagate drive was quicker overall when it came to sequential reading and writing tasks, and it also provided more battery life. The WD drive was much quicker during cold boot operations, recording 33sec compared to 47sec for the Seagate drive. We’ve compiled a table below that shows off all the performance scores, and how they compare against some recent solid state drives that we’ve tested, as well as Seagate’s SSHD hybrid drive, and WD’s 1TB Slim drive.

Seagate SSD 600Samsung SSD 840 ProOCZ Vertex 3.20Seagate Laptop Thin SSHDSeagate Laptop UltrathinWD Blue SlimWD Blue UltraSlim
Flash typeMLCToggle-mode MLCSynchronous MLCMLCn/an/aN/a
CDM* read519.8MBps523.9MBps471.9MBps110.4MBps117.4MBps115.2MBps112.3MBps
CDM* write458.3MBps500.2MBps312MBps109.7MBps115.6MBps114.8MBps106.4
File duplication265MBps265MBps192MBps46.08MBps38.43MBps44.28MBps36MBps
Battery life3hr 2min3hr 1min3hr3hr 2min3hr 5min3hr2hr 55min
Cold boot19sec19sec19sec24sec47sec35sec33sec
WarrantyThree years Five years Three years Three years Three years Three years Three years

* = CrystalDiskMark

We’ve done all this just to give you an indication of the type of storage that might soon be found in low-cost tablets and thinner-than-usual ultraportable laptops, as an alternative to costly and lower-capacity solid state drives. As far as we know, they’re not drives that you’ll be able to pick up from a computer store as an upgrade for your laptop; they’ll only be available to device manufacturers.

Related storage reviews

Seagate SSD 600 solid state drive
Samsung SSD 840 Pro solid state drive
OCZ Vector solid state drive
OCZ Vertex 450 solid state drive

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Elias Plastiras

Elias Plastiras

Good Gear Guide


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