Thunderbolt 3, USB 3.1, USB Type-C: Making Sense of Connections


Things change so quickly in the tech space that even professionals sometimes find themselves stymied by the incessant and confusing terminology surrounding certain protocols (like the ones we're going to discuss today - Thunderbolt and USB). I remember the days of 8-track tapes, but I also remember when tapes were surpassed by CDs, and CDs were surpassed by MP3s, and now how MP3s are being taken over by streaming music sources. Thinking back on those days, I was constantly barraged by new terms every day that made it difficult to slog through the buzzwords: single- and double-layer CDs, WAVs, AAC, OGG, and MP3s. I longed for the days when I recorded music to a cassette from my boombox (from AM radio stations, no less) and had to manually rewind it with a pencil stuck through the tape spool.

The same goes for Wi-Fi protocols. Yes, I remember baud modems and BBS groups and ICQ messaging. Now you kids come along with your newfangled LOLs and DDoS attacks and dual-band, tri-band rock band routers and 802.11 ac—what happened to good old-fashioned 802.11 a, b, g, and n? All relegated back to the alphabet, it seems, to be replaced by new combo terms like 802.11 ac and ax. Punk kids with your fancy Internet and your loud music.

The same thing is happening to connections. If you were using and fixing computers back in the Pentium processor days, then you may remember the pain of trying to hook up peripherals to your computer. Your mouse and keyboard needed a dedicated PS/2 connector or serial port (oddly enough, many motherboards still have this as an option). Your printer? Probably a gigantic parallel port connector that was about the size of a small flash drive these days. External hard drives? How about an old SCSI connector? And how about adding a ZIP drive with a colossal 100MB of space—that’s the equivalent of 85 floppy disks! I think you can find them on eBay, and they come with a free set of dentures.

USB took care of all of that by adding a “one ring to rule them all” mentality, with an interface (Universal Serial Bus) that was supposed to uniformly combine the speed and ease of a single interface into one connector. Unfortunately, no one told Apple, which continued to offer less popular connectors such as Firewire 400/800. USB 1 debuted in 1995 with an amazing 12 Mb/s of speed. Always concerned about backward compatibility, the USB 1.1 protocol came along, which allowed the speed to decrease to 1.5 Mb/s for slower devices. By the time USB 2.0 showed up in 2000, the speed had jumped to a whopping 480 Mb/s, and ports were backward compatible with older USB 1.1 devices—which meant your USB 1.1 device could work in a USB 2.0 port, but a USB 2.0 device would not work in a USB 1.1 port. In the same year, USB flash drives became a thing, and users were able to transfer data easily between a computer and flash drives at an appreciable rate and at a higher capacity than before.

It’s never enough. Along comes USB 3.0 (also referred to as USB 3.1 Gen 1) with superior transfer speeds of 5 Gb/s (you read that right). It’s backward compatible with USB 2.0 devices, but it will only transfer at the host computer port speed; in other words, if you use a USB 3.0 port with a USB 2.0 device, the transfer speed will only top out at 480 Mb/s. As if this weren’t as confusing as pre-calculus, we now have USB 3.1 (also referred to as USB 3.1 Gen 2), with an amazing transfer rate of 10 Gb/s, and the ability to transfer at that rate over a standard USB 3.0 cable. So if you have a USB 3.1 host port, and a USB 3.1 device, but are using a USB 3.0 cable, you’ll still see speeds of 10 Gb/s. So that’s it in a nutshell, right? Wrong. Use the chart below to get your head around USB speeds, and then we’ll talk about USB Type-C and Thunderbolt™.

Not your type?

Okay? Now we have USB Type-C. USB Type-C isn’t about the speed, it’s about the design. Before all of this, USB connectors came in different sizes: Type A, Type B, mini A, mini B, micro AB, and micro B. Sometimes, finding the right cable for your device was even more confusing than figuring out your USB speed. You also had to determine which was the correct orientation for your cable—some connected in specific configurations, and flipping a cable around in the dark or behind a cord-crowded PC was a pain. USB Type-C goes in either way, upside down or right-side up, taking the guesswork out of the plug-and-play game.

The USB Type-C connector can potentially provide up to 100 watts of power, so you can use it to power and charge cell phones, laptops, and tablets, as well. Whether or not your port or device can be powered is determined by the logo. The Power Delivery (or PD) ports are signified by a battery symbol around the logo (see below).

USB 3.0, USB 3.0 with Power Delivery, USB 3.1, and USB 3.1 with Power Delivery

Another new feature of the USB Type-C connector is its ability to send DisplayPort signals over the same cable and connector as USB signals; once a defining advantage of Thunderbolt over USB. This allows users to hook up external displays over the same simple port as their mice—nice! Unfortunately, not all computers with USB Type-C ports have to support DisplayPort over USB Type-C, so be sure to check your computer’s specs since compatibility is not guaranteed.

Bring the Thunder!

So now that we’re finished with USB types and connectors, let’s move on to Thunderbolt. Thunderbolt is a transfer technology (developed by Intel®) that provides PCI Express data and DisplayPort functionality in one cable. The chart below shows the advancements made in Thunderbolt speeds and how it compares to other protocols.

Thunderbolt also allows you to daisy-chain more than one peripheral to your existing connection. Because of the host-to-user design of USB technology, as opposed to the peer-to-peer design of Thunderbolt (and FireWire before it), USB could never connect more than one peripheral in a “chain” to your host computer —imagine using one computer, connecting an external USB hard drive to it, then trying to connect another USB hard drive to that one, and so on. USB can’t do that (unless you use a hub), but Thunderbolt can, with up to six devices. USB is also not bi-directional, which means that you can't transmit and receive data at the same time, while Thunderbolt can. Also, because Thunderbolt uses a PCIe bus, you can even add external graphics cards to Thunderbolt-equipped computers, something you can’t do over a USB bus. New USB Type-C connectors will also be directional, but that function will only be available with Thunderbolt host ports. While the original Thunderbolt and Thunderbolt 2 ports used mini-DisplayPort connectors, Thunderbolt 3 uses the USB Type-C connector for all needs. The “one cord to rule them all” is finally here.

Will Thunderbolt 3 take over all transfer protocols in technology’s near future? It certainly is appealing, with its 40 Gb/s speed and USB Type-C connectivity. It also appeals to creative professionals in audio and video recording, with its ability to transfer large files quickly for near lossless experiences. But until we see Thunderbolt 3 added as a feature to more laptops and desktops, it remains on everyone’s wish list. Hopefully, this primer on USB 3.1 vs Thunderbolt 3, with a side selection of connector types, will help you make the right decision when purchasing new equipment this season.

Have any questions, comments or concerns? I know I couldn’t include everything in this short primer, but if you have anything to add, do so in the Comments section, and we’ll get back to you as soon as we can!


Hi, my device (SURFACE BOOK 2) and it does not support THUNDERBOLT 3, and I am trying to connect to my computer external SAMSUNG X5, whether it is possible to connect it through an adapter or any other product, I would love to receive a recommendation.

Unfortunately the drive requires a Thunderbolt 3 connection and will not work with an adapter.

Thanks for your informative article. I have a couple of questions.

A. DELL XPS provides 2 USB 3.1 Type A ports with "PowerSharing" and and Thunderbolt Type C port with "PowerDelivery". What is the difference between PowerSharing and PowerDelivery?

B. Can I safely connect and operate a powered USB 3.0 Hub to a Thunderbolt 3 Type C port on my DELL XPS laptop:

1) will the two power sources to the Hub (the HUB's external power supply and the Type C port's Power Delivery) not be in electrical conflict?

2) does the 3.0 Hub itself limit transfer speed to 5 GB/sec?

thanks in advance......paul

A. USB PowerShare in this instance refers to the ability of a laptop to use select USB ports for charging connected devices even when the laptop is powered off. Power Delivery on the other hand is a newer standard that allows for more powerful USB charging up to 100W (aka faster) and bidirectional power support (theoretically can support both receiving power and delivering power from the same port). There are a few more benefits to Power Delivery, but that is the basic understanding.

B. You can safely connect powered USB hubs to a Thunderbolt port.

1. They will not be in electrical conflict as Power Delivery requires support on both devices to fully function. In this case, there will be a USB connection between the laptop and hub and the power supply for the hub will function as normal.

2. If it is a USB 3.0 hub, then yes, you will be limited to the USB 3.0 speeds of the hub.

Shawn - I appreciate your clear and prompt reply - thanks.....paul

Sorry, Im still a little confused. 

So which is better, USB C 3.1 Gen 2 with power delivery/DisplayPort or Thunderbolt 3 USB-C with Power Delivery. 

And can I do video with ThunderBolt 3 USB C? 

Thunderbolt is the better, correct? 

Thank you.

Thunderbolt 3 is better because it includes USB-C 3.1 Gen 2 (10Gb/s) and also supports 40Gb/s transfer with Thunderbolt 3 devices. You can do video with Thunderbolt.

Hi my question is I have a Presonus 24.4.2 sound board that has firewire 400. I also have a Presonus rml32ai rackmount stage box that is firewire 800. Best solution to hook these to a laptop with usb-c or thunderbolt3. Thanks

This is a bit bulky, but might be the best solution:

Other options may require a clunkier solution with multiple adapters connected to other adapters.

The 5th connector from the left (10-pin micro-B) in the image labeled "USB 2.0 and USB 3.0 Connector Types" should be a USB 3.0, not USB 2.0.

hi there, i am looking for the fastest connection setup to transfer images from an XQD card to my new macbook pro (2019). what would you suggest utilising and maximising the macbook pro capability of the thunderbolt 3 connectors? br, o.

The Atech Flash Technology Blackjet TX-1CXQ CFexpress Type B / XQD Thunderbolt 3 Card Reader would be the fastest XQD card reader we carry.

Very helpful article, even in late 2019. I recently purchased an iMac from B&H that has 2 Thunderbolt 3 ports (40Gbps transfer speed). The cable included has a rate of 50Mbps (that's mega bits). Given that the iMac only has 512MG of SSD, I'm looking to add an external HDD (looking at the LaCie d2 Prof with transfer rate of 1.9Gbps (not thunderbolt). Just wanted to confirm that to max out my potential transfer rate, I'll need a NEW cable (looking at the 20Gps StarTech).  Many thanks!


perhaps you can help me, I have an acer predator g9-791, it has a usb c connector, I wish to attach an external graphic card box in order to upgrade the nvidia 980 built in. I have a major confusion as to if the usb c jack will be able to recognize the thunderbolt data flowing from the graphic card box. the laptop has the most updated drivers and bios but still I cannot find a straight reply to my dilemma. before jumping into major expenses can you please help me out, I've seen outdated replies regarding both this laptop and graphic cards, 

much appreciated ==== ps , I do not have any idea on how to test the input abilities of this usb c jack. any ideas, thanks

The USB-C port of your computer must be a Thunderbolt 3 port to support the external chassis.  If it's just a USB port, it will not work.

If a laptop claims to have "USB 3.1 Gen 2 Type-C™ with Thunderbolt™ 3 (DisplayPort™ 1.2)" is this what is needed to host a "Thunderbolt equipped audio interface" like those from so many top manufacturers today (like UA Apollo and Arrow), offering ultra-low latency monitoring while recording, etc.? If it says this (in quotes above), is this a "Thunderbolt" equipped laptop that will work with these interfaces...or not? ...for instance, is this yet another confusing limitation of this particular "type" of Thunderbolt? I have never used Thunderbolt and am paranoid that I'll always have the wrong damn thing. 

Have a late 2015 iMac with two Thunderbolt 2 inputs.  Can’t seem to find a clear list of what external hard drives are available to utilize the 20GB transfer speed...additionally, am I just wasting my time if I’m using this connection to transfer picture files off an SD card?  Will the speed be reduced to the read/write if the SD card?


Wanted to find out if you could connect a usb 3.1 gen 2 type c port (case port) to a usb 3.0 motherboard port.  Will greatly appreciate your time and effort. Many thanks.

You would need an adapter which would allow you to connect the USB 3.1 Gen 2 Type C male cable from your computer case to the USB 3.0 female header on your motherboard.  Unfortunately B&H does not carry this kind of adapter at the moment.

Hello, I am very grateful for your page that you wrote with pictures ( the only way I can learn ). I don't pretend to understand what I am doing, so I am stumped. I am from the days of digital professional music production recorded on ADAT super VHS 8 track tapes. I finally had the budget to try and finish some of the music I have been carrying with me for 20 years. I started purchasing my hardware from PreSonus because I really liked Studio One 4, but not doing enough due diligence I picked up a mixing board and digital mixer ( CS18 / RM16 ) etc. the units both use firewire 800 connections and AVB so I had an old PC tower rebuilt to include firewire 800 ports. Once I finally had everything working I realized this tower was too slow to use virtual instruments so I was on the hunt for a used MacBook with firewire and the speed I needed but my wife surprised me with a new MacBook. Now this is what I have, MacBook Pro with as you know thunderbolt 3 and a PC Tower that has Firewire 800 and of course the old USB ( PC from 2011 ). I have my ADAT hooked direct into the RM16 via 1/4" jacks, then going out of the RM16 to the PC via firewire into Studio One 4 for tracking then I was transferring zipped songs from the PC to the MacBook using Dropbox.

I have been trying to find something else to use as an alternative to dropbox so I can transfer the music directly from the PC to the MacBook. Maybe an external hard drive which would include Firewire 800 and Thunderbolt 3 ports but I can't seem to find one. Is that what I should be looking for? Do you think a Hub is a better route or am I overcomplicating this. Is there a simpler solution? Please if you have the time can you give me some advice? I am so afraid to buy the wrong thing for this MacBook and damage it.  Thank You so much for your help.

Hi Joel - 

Designed as production-grade media, the 14TB Studio Enterprise Class 7200 rpm USB Type-C External Hard Drive from Glyph Technologies: B&H # GLS14000ENT  ( features a hard drive that spins at 7200 rpm and has a capacity of 14TB for storing data such as videos, images, music, and more. The Studio has one USB 3.1 G2 Type-C port, one eSATA port, and two FireWire 800 ports to connect to either Windows or Mac systems. Using either one of these connections, you can expect data transfer rates of up to 220 MB/s to access your content. Glyph Technologies also supports content creation products such as AVID, Pro Tools, Logic, Nuendo, Cubase, DP, Adobe CC, and more. Included with the Studio is a USB Type-C cable, a FireWire 800 cable, and an IEC power cable. Protection is provided by a limited 1-year advance replacement warranty, a limited 2-year level 1 data recovery warranty, and a limited 3-year hardware warranty.

Note: Thunderbolt 3 combines Thunderbolt, USB, DisplayPort and power via a single USB-C connector. ... Hardware commonly referred to as "USB-C devices" also will work with a Thunderbolt 3 port, but they will not be able to take advantage of the maximum speed provided by Thunderbolt 3 devices

Hi there, when I'm on the road I have an old MacBook Pro 15" Mid 2012 laptop, and I need to get a bunch of photos (I download the sd cards onto this computer) off of this hard drive onto an external drive. What would be the fastest connection available for this old laptop? I think it's thunderbolt 1 but I'm confused and need some help so I don't buy the wrong thing. I am really ill so I apologize for my stupidity here). I am looking at purchasing a lacie external drive, would love a recommendation on that too if you have one. Just need something cheap, that is fast and dependable, until I can afford to buy a new laptop, which won't be for a while...Thank you very much in advance! here are the connections available:

  • Gigabit Ethernet port
  • FireWire 800 port (up to 800 Mbps)
  • Two USB 3 ports (up to 5 Gbps)
  • Thunderbolt port (up to 10 Gbps)

Hi Sarah.  Thunderbolt would be the fastest connection on your Mac.  You can purchase a LaCie portable hard drive with Thunderbolt to take advantage of the speed.  2TB would be a good size to have but you can go for bigger if you feel you need the storage space.  The LaCie 2TB Rugged drive is both durable and reliable and would be my recommendation.

can i connect E-Gpu with my laptop using (usb 3.1 type c) connector 

USB 3.1 is not fast enough unfortunately.  To use an E-GPU, Thunderbolt 3 is required.

Unfortunately, nobody told B&H Photo writers that Firewire 400 was used, for its ability to control and capture from mini DV camcorders, with their incredible FREE iMovie and their amazing premium Final Cut Pro video editing software, which was a godsend, in education -- as well as it brought professional video editing to the masses. I actually bought my Mini DV camcorder from B&H. USB also didn't come close to Firewire, until USB 3, for transfer speeds, which was am mich as necessary, for video rendering, with an external drive. Millenial?

Geoffrey, Great valuable explanations!

 I'm still rocking a 2012 13" non-retina MacBook Pro with Thunderbolt 1 and later this year plan to get a 2018 Mac Mini with Thunderbolt 3 primarily for doing MUCH faster video editing. Until then, I want to put a very fast NVMe SSD into a USB 3.1 gen 2 enclosure for faster reading/writing of video files.

Here's My Question:  Is there an adapter or a series of two adapters that will allow me to connect an external SSD USB 3.1 gen 2 to a Thunderbolt 1 port on a 2012 mac and get 10gb/s transfer speeds --other than forking out the bucks for a Thunderbolt 2 dock with a USB 3.1 gen 2 port for the external SSD and a Thunderbolt 3 to Thunderbolt (1 and 2) adapter?  

I know the 2018 Mac Mini Thunderbolt 3 ports are compatible with USB 3.1 gen 2 with the right cable.  I also know a USB 3.1 gen 2 device can connect to a USB 3 (gen 1) port on the 2012 Mac at 5gb/s speeds.  Just hoping to do better than that and I don't think anyone is selling an NVMe enclosure with a Thunderbolt 1 or Thunderbolt 2 connector. 

Thanks in advance.

Hi Thad, that's definitely quote a dilemma you have there.  Unfortunately it doesn't look like we have a NVMe enclosure with Thunderbolt 1 or 2.  I don't know of any reputable brands that are making this kind of enclosure right now.  I think you may have to go the Thunderbolt Dock with USB 3.1 route.  But in my opinion, it's a lot of money just to use that NVMe drive you have.  Personally I'd recommend just putting the money aside and towards the Mac Mini.  The 10gb/s is also only theoretical anyway and since you plan on getting a Mac Mini later this year, I wouldn't invest too much into it.

Hi everyone. I have a HP-17-ar050wm with a Type C 3.1 Gen 1 port. I have successfully connected an external monitor via another port (HDMI) but would like to connect yet another via this Type C 3.1 Gen 1 port. Is there any possible of doing so? I have already purchased a couple of different Type C to HDMI adapters, but to no avail. I understand that my port is maxed at 5G sad to say. Any recommendations and/or help would be greatly appreciated. Thanks in advance.

Hi Pete.  It could be a number of reasons why your external monitor isn't receiving a signal.  The worse case scenario is for whatever reason, your HP just cannot support an external monitor via USB-C.  To better assist with your inquiry, please consider getting in contact with us either via Live Chat or e-mail [email protected].

Thanks for the article. I'm running several monitors and peripherals thru a docking station. The dock connects from my laptop via a Thunderbolt 3 cable. Does it make a difference if I use 20 or 40 Gb/s? Thank you

40Gb/s is just greater theoretical bandwidth and would be the better option.

Thank you for the clear easy to understand article. I am a true tech amateur. I am trying to transfer home movies from old mini dv tapes to my Mac desktop that has a thunderbolt 3 port. The camcorder has DV and USB2.0 ports. I am assuming the usb2.0 port would be better, but I’m not 100%. If I used the usb2.0 access I believe I would need a usb female to thunderbolt 3 female adapter, which I’m having trouble finding. Your expertise and advice would be greatly appreciated. Thank you! 

My apologies. I meant to write that I think I would need a thunderbolt 3 male to usb female adapter. 

Hi Lisa!  You would just need a USB-C to USB-A adapter like the one in the link below.

I'm looking at jumping from a Windows PC to a new MacBook Air and have these questions:

Will all my older USB 1 and USB 2 flash drives work with the MacBook Air USB-C ports?

Can the MacBook AIr Thunderbolt 3 video port be adapted to drive a monitor with DVI input?

Will the MacBook be able to read .jpeg, .docx, and .xlsx documents?

Thank you.

You can use your flash drives if you have the USB-C to USB-A adapter.  (

Here is a USB-C to DVI adapter for your monitor.  (

Your Mac will be able to read Jpeg files just fine.  You would need to use the Pages and Numbers apps to read .docx and .xlsx files.  

Hi, thanks so much for sharing the article and wish you had a great holiday. I know that Thunderbolt 3 has max speed of 40gb/s. When I look at LaCie website, both Thunderbolt 3 (w/ USB-C) and USB-C portable hard drive have a max speed of 130mb/s. My questions are: why is it much slower than 40gb/s; why is Thunderbolt 3 more expensive than USB-C while they have the same max speed. Thanks!

Thunderbolt is the technology and USB-C is just the port.  The max theoretical speed of Thunderbolt 3 is 40gb/s but this just means this is the max bandwidth.  Devices like external hard drives have bottlenecks.  In this case, it's the hard drive itself.  I don't think there is any drive out there that would even come close to letting you transfer 40gb/s.

Hi, I have a MacBook Pro 2018 with 4 Thunderbolt 3.0 ports. I tried to buy a LaCie Rugged USB-C, but instead came a LaCie Rugged Thunderbolt 2+USB-C .
Now I am wondering whether it was in fact a good thing (and then I could buy a MiniDisplayPort-To-USBC adapter, or whether I should return it.
The question is: with the appropriate adapter, will I have more speed buy using the Thunderbolt 2.0 cable (directly attached to the hard drive), or will I get the same speed using the removable USB-C cable provided with it, just because my Mac has Thunderbolt 3 ports?
The other question is: if I get the LaCie USBC-only version, will I be limiter to USBC transfer speed, or will I get Thunderbolt 3 speed?

Thanks for your help.

USB-C would just be the connector type.  It wouldn't make any difference if you connected the LaCie drive to your Mac with an adapter or direct connection.  You speed will be limited by the bottleneck and in this case would be the LaCie drive since it can only support Thunderbolt 2.   If you purchase a LaCie with Thunderbolt 3, your theoretical speeds would be greater than a drive with Thunderbolt 2.


I have a laptop with one Thunderbolt 3 port. I'm planning to buy 2.5" USB3.1 Gen2 enclosures, come with type C to type cable. So, does Thunderbolt 3 compatible with USB3.1 Gen2? Thanks.

I also asked the manufacturers are those enclosures compatible with thunderbolt 3 port, but no answer.

" type C to type C"

The drive should work just fine with your Thunderbolt 3 USB-C port.  Most TB3 ports support USB-C peripherals as well.  Actually, I don't recall seeing a computer with TB3 USB-C not supporting USB drives but I'm sure there are one or two out there.

I recently bough the 16TB G|RAID from G-Tech with Thunderbolt 3.  I've got it plugged in to my brand new 13in MBP but it doesn't seem to charge like it says it will.  If I plug in tradition wall power it charges and as soon as I unplug it the laptop goes into battery mode.  

Any Suggestions? 

The G-Tech G-RAID drive you have does not have the ability to power and charge your MacBook Pro.  

Very useful article, but I'm afraid it has my old grey matter spinning! I have an iMac with two thunderbolt-1 sockets, a firewire socket and a set of usb-2 sockets. I have my lacie external drive usb-c plugged into one of the usb-2 sockets. Would it increase the speed if I used the drive's usb-c lead and an appropriate adaptor into either the firewire/thunderbolt sockets?

For optimal performance, I'd like to suggest the Apple Thunderbolt 3 (usb-c) to Thunderbolt 2 adapter.  You can plug the USB-C side to the drive and connect your Mac to the adapter using a Thunderbolt male to male cable.

Thanks for the response Geoffrey. However, I have come across this statement on the Apple communities website:

"The Thunderbolt adapter is Thunderbolt only, even though Thunderbolt-3 and USB-C use the same connector.  To get USB 3 you need a Thunderbolt (not Thunderbolt-3) dock with USB 3 connectors."

Am I misunderstanding, or does this mean that the adapter is not going to help me?

Thanks again (Confused)

This is going to be a daft question, but if i have usb 2.0 device and connect it to a usb female to thunderbolt male adapter and of course plug that adapter into a thunderbolt port on my mac, will it increase my transfer speed? Or will my speed remain at the usb 2.0 default of 480

Your maximum speed would be the USB 2.0 speed.  When connecting with adapters, your speed will be limited by the this case it's USB 2.0.

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