Thursday, July 3, 2014

Reviewed: Kanex Thunderbolt to eSATA + USB 3.0 Adapter . A cheap Thunderbolt USB 3.0 alternative.

The most referring request to my website is a Google search query for a cheap Thunderbolt to USB 3.0 adapter. This comes up in the statistics everyday. I've also read countless forum requests for such a device. Before today, the only option was a Thunderbolt docking station. Thunderbolt docking stations are not portable and they start at $199.

Today, I have the next best thing: The Kanex Thunderbolt to eSATA + USB 3.0 combo adapter. No, it isn't that simple single Thunderbolt to USB adapter that everyone wants but having the eSATA add-on comes in handy. You can also get a similar device that supports USB 3.0 + Gigabit from Kanex as well.

As you can see, this model has both the blue Superspeed port and eSATA. The construction feels solid. The Thunderbolt end cable is permanently affix;making this officially a dongle. Having the cable permanently built in means you save $40 off the price of cable. However, I do feel the cable should have more girth and thickness.

This is fairly priced at $79. I was hoping for something around $40 but this is the closest thing you will get to a cheap Thunderbolt - USB 3.0 bridge. Is it expensive? I don't think so considering a USB eSATA would cost you $30. I think this matches fairly with those card-bus PCMCIA expresscard USB  3.0 adapters. $79 is also cheaper than the next option up which is $199. Furthermore, you don't have to buy a $40 Thunderbolt cable to use this.

The unit is driverless for  OSX 10.8.4 and above. Windows users can download a driver for Windows 7 and newer. I didn't have a chance to test it with my Windows Thunderbolt PC so I can't comment on Windows functionality.

Here it is in action with a USB 3.0 drive and a eSATA RAID5 attached.

A few important notes:

First it does support full 5.0 Gbps USB 3.0 throughput.
eSATA port also supplies port multiplication. SATA is up to 6G speeds.

Below are screenshots from the system profiler.

And from a 2011 27" iMac with no superspeed USB 3.0 ports.

 Now, with a simple upgraded accessory, other 2011 Thunderbolt Mac owners can have superspeed USB peripherals connected at 5Gbps.

The only negative is that it does not have a Thunderbolt daisy chain port. This will be the last item on your Thunderbolt bus. This isn't a problem for an iMac since it has two ports but I can see where an Air owner would be concerned.

This device is ideally designed for Macs with Thunderbolt produce in 2011 like the 27" iMac that I have. My two other Macbooks have USB 3.0 built in. For newer macs, this is a tougher sell product.


I tested this on my 15" Macbook Retina Pro. Since my Macbook has built in USB 3.0, I wanted to see how it compares. I've tried various USB 3.0 sticks and 2.5 inch drives and none of them had any connectivity or bus powering issues. It will definitely power most USB 2.5" external drives. So you don't have to worry about that. It won't, however, power multiple drives due to the power draw.

For my testing, the main things I am looking for are:
USB 3.0 speeds and compatibility.
eSATA speeds.

USB 3.0 Speeds.

Just for point of reference and comparison, I used a Samsung 830 SSD and OYEN USB 3.0 enclosure. I've used this in the past so it is a good reference for my old readers. I tested this with the on-board Macbook's USB and through the Thunderbolt Adapter. Here are the results.

With the KANEX adapter.

Macbook On-board USB 3.0

2011 27" iMac w/ Thunderbolt and the Kanex. Note, the iMac does not have onboard USB 3.0

The results are very close. The Samsung/Oyen is an older drive but the Macbook Pro already has an optimally fast USB 3.0 internal bus so this fares very well. I didn't have any faster drives on hand to see if it could push higher speeds (UASP).

eSATA Notes.

So how does this fair to the Seagate Thunderbolt "hack" solution featured here? Well, it is more elegant. But there are also USB to eSATA dongles out there in the market place.

Last year I tested an USB 3.0 eSATA NewerTech dongle. I tried to compare it to the KANEX but the NewerTech USB 3.0 dongle didn't mount my SANDIGITAL RAID. That particular dongle (and many other USB 3.0 to eSATA) tends to have problems with larger disk arrays.

The KANEX adapter had zero problems. The RAID box was a SansDigital TOWERRAID TR4UTBPN that was reviewed here.

The RAID is a RAID5 4 drive array and here are the results. Considering the eSATA threshold, it did very well giving me in excess of 160 MB/sec writes.

For comparison, last year's review of that box in RAID5 connected to Window's machine directly to an internal eSATA port. There is a bit of a discrepancy compared to the Windows test because the RAID is formatted NTFS which will run slower on a Mac platform.  Furthermore, I had about 3TB filled out of the 9TB.

I would say the results are very close and very good.

The Seagate Thunderbolt "hacked" solution faired a little better and you can read it here:
However, now, the Seagate is no longer the cheapest solution. This is.

There is a small gripe about the eSATA. However, it isn't the fault of KANEX. I was hoping it had eSATA-P support. Not all eSATA adapters have this so it isn't something to knock a point away. eSATA-P is a dual USB combo port that powers portable eSATA devices. like this below.

With the Kanex adapter, I couldn't power a stand-alone SSD as you see above.

Up close, this is how an eSATA-P port looks like. It is a dual socket that allows you to connect USB or eSATA. It also powers whatever SATA device you connect to it. I think the reason KANEX didn't go for anything like this because 1) I've never seen an eSATA-P with USB 3.0 speeds and 2) Having two USB ports may be too big of a power draw. Thus, the dongle is limited to something like gigabit ethernet or eSATA in addition to the single Superspeed USB port. The other eSATA-P adapters I've seen and used (ExpressCard) had to use an extra USB port to get power.


The Kanex Adapter does provide booting off eSATA. I've successfully tried it and it works without incident. However, you cannot boot off a USB 3.0 drive. As you can see in the following picture, I was able to boot 10.9.4 off a eSATA SSD enclosure. However, if you plan to do this, you have to be aware of the drive getting ejected if the computer goes to sleep. Thus, adjust your power management settings accordingly if you plan to boot off an external SATA drive.

Note. Booting is YMMV. According to different sources, booting is not officially supported and some have difficulty. YMMV (Your Mileage May Vary).

Things to Note.

Again, these are not major faults but some things to address and consider.

You can only connect so many devices. It is only rated to power a certain amount of power as specified by USB specs and how much Thunderbolt can provide. I had mixed results between my Macbook and iMac. Do not to expect to power multiple 2.5" drives off a portable USB 3.0 hub. It can't be done. Now, if you have a powered hub, then it isn't an issue.

Next, the Thunderbolt cable should have been a little bit longer to accomodate the iMac. As you can see in the picture below, the adapter doesn't fully rest to the base of the table.

I also have an issue where an Edimax USB 3.0 802.11 AC adapter will not run on my iMac as it hangs.

However, the USB wifi card runs fine on my two Macbooks. It could be a driver issue so I will look into that. I've tried a USB sound DAC and all other USB 2.0 devices worked without issues.


So far I like it. Do I have real need for this device when I already have the handy and great Caldigit Thunderbolt dock? Yep, I suppose so. Instead of buying another dock at $200 for work, I can use this where I have a lot of eSATA devices. I'd plug this in at the end of my Thunderbolt chain and plug my powered USB 3.0 hub which has gigabit ethernet built in. I'd still have a single cable connected to my Macbook in most instances.

This also comes in handy for my 27" iMac which doesn't have USB 3.0 but two un-used Thunderbolt ports. I reckon, I'd us the iMac more now.

I can see people opting for the USB 3.0 Plus Gigabit alternative also sold by Kanex. Obviously  I can see the combo USB/Ethernet can be handy for Macbook Air owners I know.

Updated Conclusion:

I thought about this a bit more after I wrote my initial review. Come to think of it, the eSATA is really the key selling point for me. Since I already have USB 3.0 on my newer macs, I don't need the Thunderbolt to USB converter functionality as much as eSATA. The only other Thunderbolt - eSATA is the LaCie which goes for $199 (without Thunderbolt cable).  I also happen to have a few eSATA enclosures that can be put to good use. I can also buy a dual SATA 6 eSATA dual bay enclosure for $80. Then if you add the price of this adapter, you can have a Striped Thunderbolt RAID set-up for under $200. Actually, if Kanex comes out with a Thunderbolt to eSATA + Gigabit adapter for $80, I would immediately pick that up too. However, based on the voice and opinions I read online, I think the this Thunderbolt to USB 3.0 was smart move. I bet this will be a very popular device soon.

Price: $79.99 direct.


  1. Great review. Found exactly when I needed it. There is very little information online, regarding the Kanex adapter.

    By the way, do you know if the ports of Kanex are bootable?

    1. Yes, eSATA boots. USB 3.0 doesn't. I updated my review to include that.

  2. Did you try booting from esata on the imac? I've tried it with my mid 2011 21.5" i7 imac and it doesn't work on esata or usb. Fine once into OS X but it doesn't see a boot drive at all... sad times.

    1. Boots the 27" iMac using this ANKER eSATA enclosure:®-eSATA-Aluminum-External-Enclosure/dp/B005B5G4S6/ref=sr_1_2?ie=UTF8&qid=1404791182&sr=8-2&keywords=anker+eSATA

      Try resetting your PRAM. And cold boot using OPTION key to select your drive.

    2. Sadly that hasn't worked. Still no joy. The esata enclosure works just fine in OS X but it's as if the machine doesn't have the right firmware for booting from thunderbolt... Not sure if that's possible. I've got the latest boot rom version, which if your machine is mid 2011 should be the same: IM121.0047.B1F (EFI 1.9)

      There's a similar vintage imac at the office. I'll give that a try... otherwise I'm at a loss.

      Interestingly, Kanex haven't got back to me.

    3. Just for completeness... Kanex have now responded to my support ticket and officially the word is you cannot boot through the KTU10. So if it does work for you, great... but don't expect it to work. Oh well. Back to firewire 800 for me, but I still think this a great peripheral as it means I can move data far more quickly even if I can't shave a few seconds off my boot time.

  3. Great article, I just got mine. I noticed that esata shows SMART status as well which is nice. Do you have 2 ssd's you could benchmark a copy from usb3 - esata or usb3 (via newertech usb3-esata adapter) - esata.

  4. The port multiplier is actually part of your enclosure, not the adapter (compare the vendor and product IDs with the screenshot from your article on the Seagate adapter); could you provide a screenshot of the system profiler page for the "Thunderbolt AHCI Controller" parent device? Also, could you comment some more on the behavior during system sleep?

    1. I updated it with a picture. It just shows it supports SATA6, AHCI version 1.20

      Regarding sleep, SATA devices attached (Docks, RAID) will disconnect after the machine goes to sleep. USB 3.0 doesn't seem to be affected from the rough sampling I've tried but all eSATA devices I used ejected.

  5. Is it working under 10.9.4 Maverick? I have the same iMac - MID 2011.

  6. You are saying that "I've tried various USB 3.0 sticks and 2.5 inch drives and none of them had any connectivity or bus powering issues. It will definitely power most USB 2.5" external drives. So you don't have to worry about that."

    Later on you say "With the Kanex adapter, I couldn't power a stand-alone SSD as you see above."

    So what gives? Can we or can we not power a 2.5" drive (specifically non-ssds, if you tried) - i have a free agent goFlex 1TB in that case.

    1. USB mode powers 2.5 drives just fine.

      eSATA mode doesn't. If you read the statement "Later on you say "With the Kanex adapter, I couldn't power a stand-alone SSD as you see above." I am referring to attaching an SSD to the eSATA port instead of USB.

      This doesn't have eSATA-P (powered eSATA) as I illustrated with the picture. There are reasons why some people want to do eSATA over USB 3.0. Namely, for concurrent I/O and lag issues. Especially booting and transferring small files.

      My statement is not contradictory. USB will power most just fine. You will have issues trying to bus power eSATA.

  7. You are saying that "I've tried various USB 3.0 sticks and 2.5 inch drives and none of them had any connectivity or bus powering issues. It will definitely power most USB 2.5" external drives. So you don't have to worry about that."

    Later on you say "With the Kanex adapter, I couldn't power a stand-alone SSD as you see above."

    So what gives? Can we or can we not power a 2.5" drive (specifically non-ssds, if you tried) - i have a free agent goFlex 1TB in that case.

    1. Read my comments above. USB will power most just fine. eSATA mode won't. This does not have eSATA-P.

  8. I have pretty much the identical hardware setup as you, and just got the Kanex (ethernet version) and a usb3 hub, and am having no luck getting two usb3 drives to be recognized. My iMac recognizes the first drive attached (with or without the hub), but not the second.
    Have you connected more than one usb3 drive at a time with the Kanex?
    (I saw your comment about the powered hub and unfortunately my cheapie hub came with no power supply, just a hole to plug in with no specs).

    1. If it doesn't show, it means it is drawing too much power. I can only connect one drive at a time unless it is attached to a powered hub. A power hub will provide power to multiple drives.

    2. I returned my cheapie/seller-didnt-sell-the-power-supply USB3 hub and went next door to Radio Shack and got their powered hub, and it works fine now...two 2TB WD Ultra Pro USB3 drives into 2011 iMac Thunderbolt via the Kanex.

      AND, I am using them via the Mac OS as a RAID 1 drive. (yes, in retrospect, it would have been less hassle, and not that much more expensive to just get the WD - My Passport Pro 4TB External Thunderbolt Portable RAID Hard Drive)

  9. Hi there,
    Thanks for your helpful writeup!
    I just got this for Christmas and am excited to use it on my early 15" 2011 Macbook Pro.

    Can you tell me:
    1) Any powered USB 3.0 hubs that you recommend?
    2) Would there be a noticable slowdown when using two external 2.5" USB 3.0 drives off of the powered hub attached to the Kanex KTU10? (I often replicate/copy files from one external to the other for backup) Or maybe a better way of saying it is: Would there still be a noticeable speed increase over my USB 2.0 ports when doing so?

    Thanks and cheers!

  10. Appreciate the tech talk 40somethinggeek. I wanted to check if you think this connection will help me. I have a current IMac with an OWC Thunder Bay 4 drive Thunderbolt enclosure. I use a Voyager with a thunderbolt to FW 800 to back up my individual drives. I have a 3TB drive that is only recognizing as 801.57 GB when hooked up through the FW 800 or USB port. Will getting the Thunderbolt to Esata connection undo this bottlenecK?? TIA, Bob

  11. Forgot to add notify me in above post

  12. Hi There,

    I am hoping you can help. I am connecting the Kanex KTU10 thunderbolt to macbook pro 15 inch early 2011 (OSX 10.10.2) and the Kanex KTU10 to Thermaltake BlacX Duet 5G docking station with USB 3 cable. The WD sata disk in the docking station appears and then is disconnected (disk not ejected properly message displayed) two times and then the disk is no longer connected. The same disk in the same Thermaltake unit connected with the same USB 3 cable directly to the USB port on the Macbook pro works fine. It does not disconnect.

    Any Input?


  13. I have a problem with the boot: when I choose an external drive esata , my IMAC 21.5 accepts the command , he turned OFF, and then back on , but before starting the boot imoiega more than 1 minute . Do you know a solution ?
    Thank you and greetings

  14. I have a problem with the boot: when I choose an external drive esata , my IMAC 21.5 accepts the command , he turned OFF, and then back on , but before starting the boot imoiega more than 1 minute . Do you know a solution ?
    Thank you and greetings

  15. Hey, Your post is very informative and helpful for us. In fact i am looking this type of article from some days. Thanks a lot to share this informative article.
    You can also see this MicFlip: World's First Reversible Micro USB Cable .


  16. hi,

    this review is interesting...

    i have buy this adapter because i want to use for boot from eSata port my second OSX Yosemite (i have Snow Leopard for first OSX)

    for connect my OWC SSD i am using this cable by AKASA ( )
    but i have some problem, probably because the eSata connector is too short respect the classic eSata cable connector...

    the OSX seems to suffer a BLOCK system...

    quest: if i buy an EXTERNAL ENCLOSURE (the Oyen MINIPRO eSata) i can resolve the problem? i can place my iMac 2011 in STOP status? or when i restart it i loose the connection to the SSD?

    i hope to have some reply, this topic is old now...

    best regard

  17. hi,

    sorry, first comment was deleted... i try to insert again...

    i have this adapter, but i have some problem with BOOT my second OSX from my OWC SSD from eSata. i have iMac 2011 i5 27".

    for booting i am using this AKASA cable:

    but i am not sure that this cable working well, probably it lost the connection to the eSata port because the connector is too short respect classic eSata cable...

    i want to buy an external enclosure to try to resolve to problem of connection (actually my OSX on SSD block to work)... with the MINIPRO by Oyen Digital i can resolve this problem?

    and again... i can go the OSX to STOP/SLEEP mode? or i lost connection when i wakeup the OSX?

    hope to have reply, best regard.