Thermaltake BlacX Duet HDD Dock - Closer Look, Testing and Final Thoughts

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Thermaltake BlacX Duet HDD Dock
Closer Look, Testing and Final Thoughts

Closer Look:

Thermaltake has a tradition of making products that look good, are functional and work very well.  The BlacX was a great product and Thermaltake improved upon it with the BlacX Duet.  It still has a nice simple design and works very well for either 3.5" or 2.5" Hard Drives.  The back of the unit is simple and you can connect the USB2.0 cable or eSATA cable for data transfer.  It uses a fairly standard 12v connector and adapter.  The top profile shows the door that springs inward to allow installation of a 3.5" HDD, while smaller 2.5" drives simply slide through the access hole in the top and are secured by the edges of this hole.

 Rear Ports
Rear Ports
 Empty Dock
Empty Dock
Top Down
Top Down


3.5" Hard Drives are installed by pushing down the spring-loaded door on the top of the BlacX.  This spring-loaded mechanism feels very solid and helps keep the drive secure when sticking up out of the dock.  Drive installation takes about 5 seconds and you can swap drives just about that fast.

 Drives In Dock
Drives In Dock
 Side View
Side View
 Big & Small Docked
Big & Small Docked


Testing & Usage:

When operated as a USB Mass Storage Device, there is no software or driver installation required in Windows 2000, XP or Vista and when you plug in the USB cable for the first time, Windows will install the drivers automatically.  When you swap drives, the removed drive will disappear from "My Computer" until you drop in a new drive.  Within seconds you're good to go with the new drive.  This works very slick and is extremely handy if you've got a few drives lying around that you want to get data on and off of without installing in a system or an external enclosure.  The BlacX Duet is also much handier than some USB to SATA/IDE adapters that require an extra cable ran for power.  While these other adapters are smaller, they generally end up in a tangle of cables and are frustrating.

When connected drives via the eSATA interface, you'll want to make sure that you have AHCI selected for your eSATA ports if you plan on hot-swapping drives.  As Thermaltake states, if you want to use multiple SATA drives when connected to the eSATA interface, you'll need a port-multiplier feature that some SATA controllers may not have.  If you can only see one connected drive when you are plugged in, this is likely the cause.  That being said, USB works without any hitches as it already has this feature.

Drive removal is as simple as holding onto the base while pulling up on the drive. You can press the front eject button if required, but I found that it was just as easy to pull the drive straight up to remove it.

We tested the performance of the BlacX Duet with HDTach and compared the results to the same drive when used internally on a SATA connection.  We are using an older SATA 1.5Mbps drive - a WD2000JB.  If you take a look back at our original BlacX review, you can see the performance comparison as we used the same drive - on USB only.

HDTach - eSATA vs USB


The performance of the BlacX Duet is pretty much what we expected.  Random access times are measured at 0.1ms longer on the USB device but CPU load is a bit higher.  The eSATA drive reports 1% CPU load with 41.8MB/s average read with a burst rate of 117.0MB/s.  When connected by USB, we see 2% CPU load with 33.0MB/s average read with a burst rate of 35.5MB/s.

As you can see, if you have an older drive, performance is pretty good when compared to the same drive connected internally.

Final Thoughts:

The Thermaltake BlacX Duet is a handy hard drive dock that makes switching drives fast, simple and convenient.  It makes hot-swapping external drives a snap and provides great performance combined with good looks.  It works with both 2.5" and 3.5" hard drives making it one of the more useful external hard drive devices around.  The addition of a second drive slot expands its usefulness and should satisfy pretty much everyone who needs access to fast external storage.  Because drive installation is completely tool-less, you can swap drives in seconds for greater productivity.  There is really nothing bad to say about this product as far as its features and functionality go, but dual eSATA drives may not work on some motherboards that don't support port multiplication.  If that is the case, you can rest assured that USB2.0 won't give you any issues, but at the cost of slower performance.


  • Works with both 2.5" and 3.5" HDDs
  • Supports mixing and matching of 2.5" and 3.5" drives
  • Simple and fast drive installation
  • Good performance over USB2.0
  • Excellent performance over eSATA
  • Attractive looks and solid construction



  • Dual drive eSATA compatibility in some systems.





I'd like to thank Thermaltake for sending over the BlacX Duet for us to review.  This is a very handy dock and is worth the purchase price in my opinion.

Please feel free to post your thoughts, comments and questions in the forum at the "Comments" link below.