Confusion over USB C dock vs. Thunderbolt 3 Dock

[jiffry1017]

Hi

I bought the new 2016 15" MacBook Pro. I'm confused about the docks. What are the benefits of getting a thunderbolt 3 dock over a usb c dock or vice versa?

Thanks.

 

[mctrials23]

USB-C is the connector type and thunderbolt 3 refers to the capabilities of the connection.

This is why you used to have thunderbolt 2 over a mini-displayport connector. The two are independent and you could implement thunderbolt 3 over a different connector type and vice versa i.e USB-C cable that isn't thunderbolt 3 capable.

A USB-C Thunderbolt 3 dock is required if you wish to run multiple things through a single USB-C port on your new macbook such as a couple on monitors, power, usb devices, ethernet etc

 

[T'hain Esh Kelch]

Thunderbolt 3 is more capable and faster than USB-C.

 

[protoxx]

Thunderbolt 3 and USB3-C are both communication protocols that use a physically similar connector. On the MacBook and newest MacBook Pro the connector works for both protocols. Other systems that may not be the case. A USB3-C connector port is not necessarily a Thunderbolt 3 port.

 

[BrianBaughn]

There's already a long thread on dongles in the forum here. The problem is...nothing has been tested as of yet.

 

[Rigby]

I bought the new 2016 15" MacBook Pro. I'm confused about the docks. What are the benefits of getting a thunderbolt 3 dock over a usb c dock or vice versa?

Essentially, Thunderbolt 3 is a different protocol from USB. It can run over the USB-C connector because the USB-C standard supports so called alternate modes. Thunderbolt 3 is such an alternate mode. It supports high-bandwidth applications such HDMI video transmission. To add to the confusion, there is also a separate HDMI alternate mode, but it only supports HDMI 1.4 (while Thunderbolt supports HDMI 2.0). You have to carefully check the capabilities of the particular dock you're interested in, but generally speaking Thunderbolt 3 docks are more powerful (but also usually quite a bit more expensive).

 

[jerryk]

USB 3.1 implements the power delivery to computer of 100W, 10 Gps USB communication (with USB 3.0 and 2.0 comparability).

Spend some time on this TB-3 faq. https://thunderbolttechnology.net/tech/faq

For your question this entry is useful

What is the difference between Thunderbolt 3 and USB-C?
Thunderbolt 3 is a superset solution which includes USB 3.1 (10Gbps), and adds 40Gbps Thunderbolt and DisplayPort 1.2 from a single USB-C port. This enables any dock, display, or data device to connect to a Thunderbolt 3 port, fulfilling the promise of the USB-C connector. See more information on the Thunderbolt Blog

So a TB-3 dock adds support the 40 Gps sec TB-3 protocol and DP 1.2. This allows the use of high-resolution daisy chained monitors, etc.

Result is TB-3 dock = TB USB 3.1 dock + TB-3 feature support.

 

[Rigby]

What is the difference between Thunderbolt 3 and USB-C?
Thunderbolt 3 is a superset solution which includes USB 3.1 (10Gbps), and adds 40Gbps Thunderbolt and DisplayPort 1.2 from a single USB-C port.

This is a little bit misleading since a non-Thunderbolt USB-C port can also support Displayport (version 1.3) using a different alternate mode. So a non-Thunderbolt dock may allow the use of DP as well.

 

[InsertCatchyNic]

Damn, I have never seen so many words spent not answering a question by trying to answer the question using a whole bunch of buzzwords and terminology.

Long story short, if you plan on running a 4K display from the dock then you should get yourself a thunderbolt 3 dock. If all you want to do is add a dock that will act more as a port replicator (adding some usb 3.x connectors, a ethernet connector, smart card reader, etc.) then save your money and buy yourself a USB-C dock.

The Belkin Thunderbolt 3 dock that everyone is talking about will set you back almost $500 (rumor has it) a USB-C dock from OWC will set you back about $179.

 

[jerryk]

The Belkin Thunderbolt 3 dock that everyone is talking about will set you back almost $500 (rumor has it) a USB-C dock from OWC will set you back about $179.

That is the "early adopter" penalty. I plan on being a "later adopter" and waiting until next summer/fall to upgrade. By then there should be multiple dock options at lower prices and Kaby Lake quad core processors in MacBook Pros.

 

[JTToft]

For displays, a plain USB-C dock will only do up to 4K 30 Hz without compromising its other connections. A Thunderbolt 3 dock can do up to 2 x 4K 60 Hz or 1 x 5K 60 hz without compromising its other connections.

A Thunderbolt 3 dock will also typically be capable of delivering more power to the Mac than a USB-C dock, though not necessarily.

 

[dyn]

Thunderbolt 3 and USB3-C are both communication protocols that use a physically similar connector.

USB3-C doesn't exist. There is Thunderbolt and there is USB. There is also USB-C but this is only a connector and cable which can be used to carry either Thunderbolt or USB. Currently all USB-C docks are in fact merely USB docks so they don't use Thunderbolt 3.

The difference between USB and Thunderbolt can be quite big. The biggest difference is usage. Thunderbolt is also a more robust protocol meant for high speed data transfers (it has a higher bandwidth, lower latency and some other nifty stuff) whereas USB has been used for simple peripherals (keyboard, mouse, printers, etc.) and has been beefed up over the years (it now goes up to 10Gbps but it doesn't have the low latency Thunderbolt has). Because of this USB is quite simple and cheap whereas Thunderbolt is complex and expensive. You'd generally use USB for simple devices that any consumer would use and use Thunderbolt for more high end devices that professionals and demanding consumers would use. If you'd need a comparison: it's a simple 2,5" disk vs a 5-disk (or even more) RAID array.

So long story short: you'd get a Thunderbolt 3 dock when you need those higher speeds and/or when you want something robust. That's usually the case when you have something like a RAID cabinet, 4k 60Hz display (or even 5k), high end A/V devices, etc. If you don't have any of those you'd simply get the USB dock because it will work fine at a lower cost.
One thing to add: currently there are more USB versions than Thunderbolt 3 versions available so that would be one more reason to buy the USB version. Or a reason to wait a little

Thunderbolt 3 is a superset solution which includes USB 3.1 (10Gbps)...

USB 3.1 consists of 2 different kinds: Gen 1 (aka USB 3.0 which does only 5Gbps; this is used in the current and previous MacBook) and Gen 2 (used in TB3 and thus in the new MBP). Manufacturers really need to mention which gen their USB 3.1 implementation is, else there is even more confusion.

 

[jiffry1017]

Long story short, if you plan on running a 4K display from the dock then you should get yourself a thunderbolt 3 dock. If all you want to do is add a dock that will act more as a port replicator (adding some usb 3.x connectors, a ethernet connector, smart card reader, etc.) then save your money and buy yourself a USB-C dock.

The Belkin Thunderbolt 3 dock that everyone is talking about will set you back almost $500 (rumor has it) a USB-C dock from OWC will set you back about $179.

For displays, a plain USB-C dock will only do up to 4K 30 Hz without compromising its other connections. A Thunderbolt 3 dock can do up to 2 x 4K 60 Hz or 1 x 5K 60 hz without compromising its other connections.

A Thunderbolt 3 dock will also typically be capable of delivering more power to the Mac than a USB-C dock, though not necessarily.

Thanks! This is what I was looking for. I had researched info prior to posting about how Thunderbolt 3 and USB C relate to each other in terms of connector type, etc, but I wasn't sure until now why I would choose thunderbolt over USB C or vice versa.

When you say thunderbolt can deliver more power to the mac, what kind of power are you talking about? It's not charging right? Like more watts? I'm guessing you mean it can handle more premium equipment/monitors/etc.?

 

[JTToft]

When you say thunderbolt can deliver more power to the mac, what kind of power are you talking about? It's not charging right? Like more watts? I'm guessing you mean it can handle more premium equipment/monitors/etc.?

- No, I mean charging. It seems most plain USB-C docks and monitors can only deliver up to 60 W of power, while Thunderbolt 3 ones can go up to 85 W. I'm not totally sure if it's due to a technical limitation or just a design choice made when USB-C accessories were mostly designed for the 12" MacBook. Maybe someone can shed some light on that?

 

[jerryk]

- No, I mean charging. It seems most plain USB-C docks and monitors can only deliver up to 60 W of power, while Thunderbolt 3 ones can go up to 85 W. I'm not totally sure if it's due to a technical limitation or just a design choice made when USB-C accessories were mostly designed for the 12" MacBook. Maybe someone can shed some light on that?

That was a choice made by the dock creators. The USB Power Delivery specification supports up to 100 W. The following is from the USB group, there is no requirement for any dock to implement these features, but the spec defines them is they are implemented.


USB Power Delivery offers the following features:

• Increased power levels from existing USB standards up to 100W.
• Power direction is no longer fixed. This enables the product with the power (Host or Peripheral) to provide the power.
• Optimize power management across multiple peripherals by allowing each device to take only the power it requires, and to get more power when required for a given application.
• Intelligent and flexible system level management of power via optional hub communication with the PC.
• Allows low power cases such as headsets to negotiate for only the power they require.

 

[JTToft]

That was a choice made by the dock creators. The USB Power Delivery specification supports up to 100 W. The following is from the USB group, there is no requirement for any dock to implement these features, but the spec defines them is they are implemented.


USB Power Delivery offers the following features:

• Increased power levels from existing USB standards up to 100W.
• Power direction is no longer fixed. This enables the product with the power (Host or Peripheral) to provide the power.
• Optimize power management across multiple peripherals by allowing each device to take only the power it requires, and to get more power when required for a given application.
• Intelligent and flexible system level management of power via optional hub communication with the PC.
• Allows low power cases such as headsets to negotiate for only the power they require.

- Yes, 100 W is the maximum. I just wonder if there's some limitation on under which circumstances USB-C can deliver that much - say if it also has to drive a 4K monitor at 60 Hz and provide USB, etc. There shouldn't be, I suppose. But the 60 W limit just seems a strange choice to make especially on the LG UltraFine 4K (which, as opposed to most docks, was introduced after the latest MacBook Pro announcement) if higher wattage is possible without problems.

 

[jerryk]

- Yes, 100 W is the maximum. I just wonder if there's some limitation on under which circumstances USB-C can deliver that much - say if it also has to drive a 4K monitor at 60 Hz and provide USB, etc. There shouldn't be, I suppose. But the 60 W limit just seems a strange choice to make especially on the LG UltraFine 4K (which, as opposed to most docks, was introduced after the latest MacBook Pro announcement) if higher wattage is possible without problems.

Good question. It seems that the LG UltraFine 5K can deliver more power so perhaps they are targeting the 4K for lower power requirement systems. From the 5K description on the Apple site:

A single Thunderbolt 3 cable (included) provides up to 85W of charging power to your MacBook Pro with Thunderbolt 3 (USB-C) ports. And three downstream USB-C ports (5 Gbps) offer additional connectivity and power to compatible devices and accessories.

Connect the UltraFine 5K Display to your MacBook Pro via an included Thunderbolt 3 cable, which supports 5K video, audio, and data simultaneously — all while supplying up to 85W of charging power to your MacBook Pro. And with seamless macOS integration, you can control volume and brightness on your 5K display without the need for physical buttons.


http://www.apple.com/shop/product/HKN62LL/A/lg-ultrafine-5k-display


For me power from the monitor, and the monitor acting as the hub, is the design I have been waiting for, and show the real reason to have USB-C. One port to rule them all.

 

[JTToft]

Good question. It seems that the LG UltraFine 5K can deliver more power so perhaps they are targeting the 4K for lower power requirement systems. From the 5K description on the Apple site:

For me power from the monitor, and the monitor acting as the hub, is the design I have been waiting for, and show the real reason to have USB-C. One port to rule them all.

- Indeed. But why would they not enable 85 W on the 4K? Just to upsell to the 5K one for 15" users? I suppose that's possible. Still seems strange if the 60 W choice across virtually all USB-C power capable accessories is mere coincidence.

You're crippled in quite a lot of areas if you choose the smaller monitor for your MacBook Pro:
Less power, slower USB, no webcam, no microphones, and no 10-Bit colour.

 

[jerryk]

- Indeed. But why would they not enable 85 W on the 4K? Just to upsell to the 5K one for 15" users? I suppose that's possible. Still seems strange if the 60 W choice across virtually all USB-C power capable accessories is mere coincidence.

You're crippled in quite a lot of areas if you choose the smaller monitor for your MacBook Pro:
Less power, slower USB, no webcam, no microphones, and no 10-Bit colour.

The USB power deliver spec defines different levels of voltage and current requirements. To get to the 45-60W you need to have 20V @ 2.25-3.0 A. To get to 100 W you need to have 20V @ 5.0 A. My guess is that power supplies that provide 20V @3A are more readily available and cheaper since this is real close to what a lot of lower/mid end PCs use (19.5 @ 3.35). And when you move up 20V @ 5A you are into a lower quantity unit that is more costly to supply. Also, anyone looking for a specialty product like a 5K monitor with a dock is more likely to have the top end 15 new MBP and has the budget.

So IMHO, what you see is combination of higher component prices and market segmentation.