“Standards are great! There are so many to chose from.” anon
This article is the result of my quest to future-proof a purchase of a Thunderbolt/USB hub. I thought I’d pass on this information.
I wanted to see If I can connect my MBPr (late 2013) to a hub with a single cable. My MBP has these ports - 2 USB 3.0, 2 Thunderbolt 1 and 2, headphone jack, HDMI, MagSafe.
Note[ This is my 3rd crack are writing this article. The deeper into the rabbit hole I went (see title). the less clarity there was about which came first. Exploring that hole and a 5-week Covid experience leads to today. (I cannot recommend Covid to anyone especially at age 79. I’m now vertical and trying to re-gain 22 lbs but I do feel great. Mask up.]
Starting with USB4 and Thunderbolt Announcements.
- introduces the Type C adapter as the logical follow-on to Types A and B.
- USB4 deprecates all Type A and Type B connectors.
- USB4 announces using the Thunderbolt Spec 3 for their next high-speed standard in pursuit of a higher transfer rate.
- announces Thunderbolt (in collaboration with Apple). Intel analyzed types of data transfers and concluded there were only two types - high-speed transfers of video/audio via Display Port, and memory/storage via PCIe. These are well-established standards already in use in Apple and PC devices.
- adoption of the Type C connector.
- Thunderbolt 4 was announced in early 2020.
- is the first computer manufacturer to jettison the use of all USB connectors but Type C (for some MacBooks so far).
- in June 2013 introduced Thunderbolt implementations of specs for 1 and 2 with USB Gen 3.1 and Gen 3.2 respectively.
- This support page, Identify the ports on your Mac - Apple Support shows the Thunderbolt and USB connectors for various Apple computers. Note: these pages point out the differences between the Mini-DisplayPort connector for Thunderbolt 1 and 2, and older Mini-DisplayPort connections for video. These differences are:
- for Thunderbolt the lightning bolt symbol appears on both the chassis port and male cable plug cover and has a white block inside the connector.
- for the original Mini-DisplayPort connector, the old symbol in both places and has is no white insert.
Intel Shares Details on Thunderbolt 4, Launching Later This Year 07/08/20
Benefits to the computer manufacturers:
- elimination of some device cards
- elimination of continual changes to the laptop chassis (carving holes) due to Type A and Type B changes.
- elimination of the balancing the mix and match of Type A and Type B connectors. These mixes never seemed to satisfy all users.
Benefits to Intel
- Intel revenues are down with Apple’s departure and the race to the bottom of low-cost netbooks and laptops.
- Apple’s collaboration with Intel on Thunderbolt provides a path to large-scale display setups and to mass data storage devices up to 3,500 GBps.
- USB4’s collaboration with Intel provides access to a path to high-end (4K, 5k, 8K) video demands.
Benefits accrue to the Hub manufacturers:
- more sales obviously
- but, the mix and match of ports and various hub configurations will now be moved to the hubs at a cost to the end-users.
Benefit to end-users
- provides a hub with a single power source and up to four Type C ports, and hopefully some future-proof improvements to new adapters. Hopefully.
Speeds and Feeds
USB version history
Group* Spec (initial version names) USB-IF branding (EU) previous names
UBS1 USB 1.0
“” USB 1.1
UBS2 USB 2.0 (2.0 and an enhanced version of 2.0)
UBS3 USB 3.0 (USB 3.2 Gen 1, Superspeed USB 5Gbps)
“” USB 3.1 (USB 3.2 Gen 2, Superspeed+ USB 10Gbps) note the mix of Gen 3.2
“” USB 3.2 (USB 3.2 Gen 2x2, Superspeed+ USB 20Gbps) “ Confusing, no?
USB4 (USB 4.0 ?)**
- USB4 added USBn nomenclature to simplify/clarify the alphabet/number soup especially to USB 3.n.
Adapters and speeds in Gbps (Gigabits per sec).
Protocol Adapter Gbps (Type A and A2, Type C, and DP - Display Port
USB 1.0 A 0.0015 low speed
USB 1.0 A 0.012 high speed
USB 2.0 A/C 0.480 the C adapter is backward compatible to 2.0
USB 3.0 A/C 5
USB 3.1 A2/C 10 Reversible connector introduced (identified by the blue block inside the connector)
USB 3.2 A2/C 20
USB (4.0 ?) ** C 40 Thunderbolt 3 Spec adopted; all Types of A and B deprecated
TB 1 DP 10 Thunderbolt 1/USB 3.1 (available my Apple MPB Late 2013) TB 2 DP 20 Thunderbolt 2/USB 3.2 (available my Apple MPB Late 2013) TB 3 C 40 TB 4 C 40 Merged USB4 specs with internal changes (see USB links above).
Hint: divide rates by 8 to get Bytes per second
To put a finer point on the use of Type C in nomenclature. USB-C, USB Type C, Thunderbolt-C, or Thunderbolt Type C would be formally correct. Otherwise, Thunderbolt and USB4 would be more informal because “Type C" and “-C" are redundant since only one connector type is defined. Journalists use Thunderbolt 3 which describes the 40 Gbps spec and not the connector. But remember Thunderbolt is only part of the big picture. USB4 is the other.
Moving on to the cable between the two Type C connectors, first, look at the pin-out diagrams in the respective Wiki pages - Thunderbolt shows the use of 20 pins, USB4 24 pins. Search for Google Images of these connectors, you’ll see what looks like a double-deck bridge. There are 4 high-speed lanes on each side and some low-speed lanes, and other sundry pins for control, power, and ground. End to end there are 11 pieces-parts - a 24 line cable in the middle, two Type C adapters and 2 connectors, a pair of chips for each side of the Type C adapter, and computer/hub OS data processing senders/receivers reading and feeding each chip. Thunderbolt cables are short (.5 to 3-4 meters), can be passive or active connectors, and expensive.
My mind boggles at this point. Here’s a teaser. When you reverse the connector upon plugging in, the signal at pin 1 now aligns with pin 24. How can the signals be flipped so that pin 1 aligns virtually with pin 1?
** as of 2/5/21 I have found announcement dates made in early 2020 for USB4 and Thunderbolt 4 but could find no release dates for either. However, rollouts are beginning now.
My take on this is that the USB4 and Thunderbolt 4 merged release have agreed on pin usage and are aligned so they play nicely together. The third USB link above is from July 2020 further describes the USB4 requirements of certification, direct memory access, data and video speed, number of ports, charging, and wake up. Apple M1 is not certifiable.
Wrap-up on my Quest
Well, my quest for the perfect hub is not in sight but the above OWC and CalDigit models might last for one or two computer upgrades.
My perfect hub would be a powered brick that contains nothing but Type C ports and a power source of some high wattage. The peripherals would connect to Type C male adapters (aka, use short dongles), e.g. a Lightning cable to Type C. When you order the hub, you would also order a small handful of dongles to suit your needs, connect them up other peripherals, and put them anywhere in the brick. That would be future proof.
But alas, this is not to be. But the OWC hub is looking good. But at $249.00. Maybe. I’ll have to see how this stacks up with the competition.
CES 2021: OWC Introduces Thunderbolt 4 Dock, New Storage Drives, and More
CalDigit’s Latest Dock Features Four Thunderbolt 4 Ports and Four USB-A Ports
- I do know the charging capability for my MBP cannot be used. But the hub is future-ready.
- My USB Type A connectors should be to plug into any USB port because USB is backward compatible to USB 2.0.
= My audio connector is good as is.
- My Thunderbolt 1 and 2 are convertible using new cable adapters, e.g. there is a Thunderbolt MiniDisplay to Type C cable available.
I‘m not clear as to the HDMI port. If can be shunted over Thunderbolt, there is a Type C adapter that converts to HDMI at the monitor.
- On the System Information page, you may see the Thunderbolt 1 10Gbps and Thunderbolt 2 20Gbps implementation. What’s not shown is the underlying USB Gen 2 (10 Gbps) and Gen 2x2 (20 Gbps) added to these protocols. I deduce this because my G-Drive external drive uses USB Gen 3.1 and this always shows as a Thunderbolt 110 Gbps connection even when the Mini cables were swapped.
Wrapping up this article
I hope the above helps with understanding the alpha/numeric soup, performance gains made over time, and some things about Thunderbolt and USB. Digging into the links above, you’ll find the manufacturers who make up the consortia for the various specifications, more about the history timelines, and much more detail.
The final nomenclature will be interesting. Repetitious typing of "Type C” and "USB4” as I have done and “Thunderbolt / USB 4” as Apple has done on the above link is just plain painful. “Thunderbolt / USB 4” is correct in that it recognizes the joint venture and numeric sequence. However, folks want and will makeup shorthand names.
I would prefer "TU 4.0”.
My background covers 53 years of computer technology. This began with end-user/computer system programming/management and ended as a senior technical consultant to large and small companies and third-party developers to build high performance, fault-tolerant programs with SQL databases and various communication protocols.
Hope this helps. Please contact me for questions, corrections, comments.
regards, Mike Noonan