Thunderbolt 3 vs USB 3.1 Docks (USB-C)

Hi all,

Given I am now an owner of the 2017 HP Spectre x360 13", it only has two USB-C and one USB-A. The USB-C port supports Thunderbolt 3 or USB 3.1 Gen2. My Dell Precision 7710 also has a USB-C / TB3 port.

So here's what I am trying to decipher among the currently available products: Why would I choose a TB3 dock over a USB 3.1 Gen2 Dock? Yes, I realize the bandwidth difference here is 40 Gbps vs 10 Gbps. That said, a lot of the peripherals out there just say they are "Thunderbolt 3 Compatible" but does that just mean they work on the Thunderbolt 3 port? I haven't researched this further, but shouldn't ALL Thunderbolt 3 ports support USB 3.1 Gen2? I realize not all USB-C ports will support Thunderbolt, and some USB-C can be USB 3.1 Gen1 (aka USB 3.0) or USB 3.1 Gen2.

My situation is that as an AV Engineer and Programmer, I regularly need connectivity on the road. I would to expand to two Gigabit NICs, an HDMI port (single, with 4K/60). I don't think this calls for needing TB3 bandwidth, but if there's an actual Thunderbolt 3 to HDMI adapter, I'm interested.

The key thing for me is ensuring each port is capable of full bandwidth.

I'm currently looking at this and this.

I'd be interested in a TB3 dock if it had HDMI (instead of DP-- I know the spec uses DP), USB-C PD to 45W, Gigabit Ethernet, and the USB-A ports were 3.1 Gen2. I'd rather it have a USB-C power inlet, as opposed to a DC barrel plug, which would be just another PSU to carry around.

 

The reasons someone would want Thunderbolt-3 vs USB 3.1g2:

1) Higher overall bandwidth (40Gbps vs 10Gbps)
2) Daisy-chain devices
3) Access to PCIe (via Thunderbolt-3 controller)

So, scenarios where this matters for each reason:

1) You are driving high-resolution monitors (usually multiple of them); Or , you need to transfer lots of data over removable storage (usually RAIDed SSD arrays).

For you, 4K60 uses 18Gbps (on 8-bit, non-HDR content) which means you automatically need Thunderbolt-3. Furthermore, you actually WANT DisplayPort instead of HDMI. To drive 4K60 over HDMI, you will need HDMI 2.0. That's rate to find on computer monitors, and rare to find on docking stations. The only time 4K HDMI is used in the computer world is when you're plugging a modern video card (GeForce 9-series or 10-series) into a 4K HDTV.

If you are plugging in to an HDTV, get a DisplayPort-to-HDMI 2.0 adapter. If you are just going from docking station into a computer monitor, stick with DisplayPort.

2). Some setups benefit from the ease of setup from daisy chaining.

3) Some scenarios benefit from direct access to PCIe, such as externally-mounted RAID cards or externally-mounted GPUs.

So for you, you will need Thunderbolt simply because you need the bandwidth to drive 4K60. USB 3.1g2 will it handle it, unless you are willing to deal with some screen lag.

Sent from my SM-G935V using Tapatalk

 

I would be using 4K/60 connectivity for testing pro-video systems, not connecting to computer monitors... which is why HDMI would be required.

So if 99% of the time connecting 1080p/60, I am figuring USB-C is completely fine.

Also, most of the TB3 peripherals I see (including cables) only state that they are 20Gbps bandwidth, unless 40Gbps stuff isn't out yet.

It definitely seems like I'm going to need more than 1 adapter/dock.... 1 dock to rule them all doesn't seem like a reality.

 

Another follow up. I think I am going to try out that CHOETECH USB-C unit. No, it won't get me 4k/60, but that would be a rare need. However, it seems to be the only type of unit that will get me a 1080p HDMI output (which is needed more often than DisplayPort), gigabit Ethernet, and supports Power Delivery.

None of the TB3 docks I've looked at seem to support charging, or if they do, require their own DC adapter..

Of the TB3 docks announced or available, I don't need a lot of the features on them including audio in/out, FireWire, mini-DP, etc.

What I would be in the market for would be simple single or dual port TB3 adapters (potentially cheaper than docks) that have 4K/60 output... not full docks.

I'm also interested in other high-speed adapters such as TB3 to ExpressCard or TB3 to M.2 PCIe.

 

How does this Anker USB-C to HDMI 2.0 adapter work to get around the 10 Gbps bandwidth of USB 3.1 Gen2? Is it 4:4:4 color?