User773
1 Copper

Dell Thunderbolt Dock TB16 Maximum Cable Length

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I have a Dell Thunderbolt Dock TB16 - 240W docking station for the XPS 15 9560. It comes with a 0.5m USB Type-C Thunderbolt cable. Is there a longer cable, such as a 1m cable available for the TB16?

The TB16 was shipped from Dell with an instruction booklet entitled "Thunderbolt 3 (USB Type-C) Dock Cable Installation Guide." The book has instructions on how to remove the shipped cable and replace it with some cable that is received as a separate shipment. Does anyone know the purpose for those instructions? 

I'd like to suggest that the above questions would be a nice addition to the TB16 FAQ... adding some info on cable length, cable length restrictions, future plans for differing cable lengths, etc., might help users such as myself. I see others out there which have concerns about short cable length so that's why I think the answer to the above would make good TB16 support KB articles or FAQ entries. 

Thank you!

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Saltgrass
4 Ruthenium

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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The included instruction guide is just in case you need to remove the cable for replacement.

My cable is around .4 meters or 16 inches.  I do not know of other length cables are available.

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XPS 2720, Inspiron 17 7779, Inspiron 15 7567, XPS 13 9365, Inspiron 1545, TB16 Dock

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OGDreseller
1 Copper

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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The max length for 40Gb/s is .5m, which the TB16 comes with. You can get up to 2m at 20Gb/s, but the extra connector (using an extension rather than just a new longer cable) would also degrade the signal and transfer speeds.

blog.startech.com/.../

en.community.dell.com/.../20008702

[Source: https://www.reddit.com/r/Dell/comments/622fnz/tb16_extension_cable/]

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jphughan
5 Rhenium

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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Just an update to this.  StarTech is now selling Thunderbolt 3 ACTIVE cables that can do 40 Gbps up to 2 meters.  Active cables have circuitry built into the cable to maintain signal integrity at longer distances and compensate for degradation that occurs when crossing the connectors, hence the improvement. The catch is that Thunderbolt 3 active cables cost $60-90 apiece.

If you're still interested, another spec to watch out for is the maximum power delivery.  The 2-meter cable can only pass 60W, while the 1-meter cable is rated for the full 100W (which I just confirmed with StarTech after they escalated internally since the 1-meter product page listed 60W and 100W in different places, and the Amazon page still says 60W).  Of course Dell says their dock can provide 130W to Dell devices, but since the Thunderbolt 3/USB-C official max is 100W (20 volts @ 5 amps), you likely won't find a cable officially rated for more than 100W. Dell is doing something proprietary there. If I had to guess, I'd say they're raising the voltage, in which case the cable should have no problem going to 130W since higher voltage doesn't impose additional requirements on cabling. If on the other hand they're raising the amperage, the cable MIGHT not be able to handle it since higher amperage does require thicker wires. But I still say "might" because in this case, the fact that the cable is rated for 100W doesn't necessarily mean it couldn't handle 130W. It could just mean that they only TESTED it up to 100W because again, that's the official max in the spec.

If you buy one of those cables though, please do report back as to how it goes!

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Saltgrass
4 Ruthenium

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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The included instruction guide is just in case you need to remove the cable for replacement.

My cable is around .4 meters or 16 inches.  I do not know of other length cables are available.

----------------------------------------------------------------------------------


XPS 2720, Inspiron 17 7779, Inspiron 15 7567, XPS 13 9365, Inspiron 1545, TB16 Dock

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OGDreseller
1 Copper

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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The max length for 40Gb/s is .5m, which the TB16 comes with. You can get up to 2m at 20Gb/s, but the extra connector (using an extension rather than just a new longer cable) would also degrade the signal and transfer speeds.

blog.startech.com/.../

en.community.dell.com/.../20008702

[Source: https://www.reddit.com/r/Dell/comments/622fnz/tb16_extension_cable/]

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User773
1 Copper

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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Thank you... I had seen that Startech article and was actually hoping to find a 1m cable in exchange for the lost throughput but I was hoping to avoid an extension type of thing for the reasons you mentioned. Since I only have one 1080p monitor (not 4K), and only use USB drives and Ethernet on the dock, seems like I might be able to easily get by with a longer cable. Sounds like there is no replacement cable from Dell at this time. Thank you for helping to clarify that!  

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User773
1 Copper

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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Saltgrass thank you too for the info on the booklet. Dell support told me it was included because when they send out a replacement dock, it comes without the cable. I have not confirmed that... heard it from a front line support person. What you mention seems to be related to that answer.

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jphughan
5 Rhenium

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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In your case you should consider the WD15 USB-C dock. It's limited to dual 1080p displays because it only uses USB Type-C rather than Thunderbolt, but that also means it can use a longer cable -- and it's cheaper. However, I haven't investigated whether the dock side uses the standard connector. If it does, just make sure the cable you buy supports USB 3.1 Gen 2 (10 Gbps) AND 5A/100W charging, since some only do 3.1 Gen 1 or even 2.0 and only 3A/60W charging. Note that there isn't an official spec for the 130W charging that Dell docks offer (only with Dell systems), but I'm fairly sure that's achieved only with a higher voltage rather than amperage, so it SHOULD be fine.

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jphughan
5 Rhenium

RE: Dell Thunderbolt Dock TB16 Maximum Cable Length

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Just an update to this.  StarTech is now selling Thunderbolt 3 ACTIVE cables that can do 40 Gbps up to 2 meters.  Active cables have circuitry built into the cable to maintain signal integrity at longer distances and compensate for degradation that occurs when crossing the connectors, hence the improvement. The catch is that Thunderbolt 3 active cables cost $60-90 apiece.

If you're still interested, another spec to watch out for is the maximum power delivery.  The 2-meter cable can only pass 60W, while the 1-meter cable is rated for the full 100W (which I just confirmed with StarTech after they escalated internally since the 1-meter product page listed 60W and 100W in different places, and the Amazon page still says 60W).  Of course Dell says their dock can provide 130W to Dell devices, but since the Thunderbolt 3/USB-C official max is 100W (20 volts @ 5 amps), you likely won't find a cable officially rated for more than 100W. Dell is doing something proprietary there. If I had to guess, I'd say they're raising the voltage, in which case the cable should have no problem going to 130W since higher voltage doesn't impose additional requirements on cabling. If on the other hand they're raising the amperage, the cable MIGHT not be able to handle it since higher amperage does require thicker wires. But I still say "might" because in this case, the fact that the cable is rated for 100W doesn't necessarily mean it couldn't handle 130W. It could just mean that they only TESTED it up to 100W because again, that's the official max in the spec.

If you buy one of those cables though, please do report back as to how it goes!