This article describes the main differences between Thunderbolt 3 and USB 3.1 (USB-C).
The USB-C connector is used in Thunderbolt 3 mainly because it is compact. However, the compatibility of these two technologies is limited.

Below are answers to frequently asked questions about Thunderbolt 3.

How can I tell if my computer has a Thunderbolt 3 port?
Check your computer's documentation. The Thunderbolt 3 port on your computer looks like a USB-C port with a Thunderbolt icon (lightning bolt icon). See illustration below:

Can I use a USB 3.1 (USB-C) drive instead of a Thunderbolt 3 drive?

• The Thunderbolt 3 computer port supports both the interface of the same name and USB-C.
• The computer's USB 3.1 (USB-C) port only supports USB devices.

Can I use a USB 3.1 (USB-C) cable instead of a Thunderbolt 3 cable?

• Thunderbolt 3 cables support Thunderbolt 3 and USB 3.1 (USB-C) devices.
• USB 3.1 (USB-C) cables do not support Thunderbolt 3 devices.
• To use a Thunderbolt 3 drive on your computer, you must have a Thunderbolt 3 cable and a Thunderbolt 3 port.

Are USB 3.1 and Thunderbolt 3 different in performance?

Protocol	Estimated Pulse Rate Gigabit per second (Gbps)	Logo
USB 3.1 Gen 1	Up to 5 Gbps
Based on USB 3.1 Gen 1 platform	Up to 5 Gbps
USB 3.1 Gen 2	Up to 10 Gbps
Based on USB 3.1 Gen 2 platform	Up to 10 Gbps
Thunderbolt 3	Up to 40 Gbps

Are Thunderbolt 3 drives compatible with previous versions of the interface (Thunderbolt and Thunderbolt 2)?
Thunderbolt 3 drives are compatible with Thunderbolt 1 and 2, however, since Thunderbolt 3 uses a different interface, an adapter is required. Additionally, some Thunderbolt 3 features, such as charging, are not supported in previous versions of Thunderbolt and may not work when using an adapter. It should also be noted that not all adapters are reversible, so if you connect a Thunderbolt 3 drive to a Thunderbolt 2 or Thunderbolt 1 computer (and vice versa) using an adapter, the device may not work.

Some of our Thunderbolt drives offer multiple interfaces (such as Thunderbolt 3 and USB 3.1), allowing them to be used with systems that do not support Thunderbolt 3 technology.

Note. All adapters are not guaranteed to be fully compatible with Thunderbolt 3 devices.

Are all Thunderbolt 3 (USB-C) cables the same?
No. There are two types of Thunderbolt 3 (USB-C) cables: passive and active. Passive ones are cheaper and provide data transfer rates of up to 40 Gbit/s (with a length of up to 0.5 m) and 20 Gbit/s (with a length over 0.5 m). Active cables allow you to achieve speeds of up to 40 Gbit/s with a length of up to 2 m.

I think almost all of you know that there is such an interface as Thunderbolt 3 (TB3). This is the latest version of Thunderbolt.

The first version of TB, developed by Intel and Apple, appeared in 2011. I will not delve into the history of this interface, since this article will not be about that. Just so you know, the first laptop with the first version of TB appeared in 2011.

The first and second versions of the interface had unique connectors. They were quite rare and did not gain much popularity. The reason is the relative high cost. The fact is that in order to equip their device with a TB port, manufacturers had to not only buy a not-so-cheap controller, but also pay licensing fees to Intel.

The TB3 interface appeared in Apple laptops in 2016. Its main feature is that the port is no longer unique, but a completely ordinary USB-C. And here it’s probably worth chewing on it. Why? Because I have already met people working in IT and well versed in hardware who confused Thunderbolt 3 with USB-C.

So, first of all, it’s worth noting the uniqueness of the USB-C port. The point is that it has so-called alternative modes. To simplify, this means that the USB-C connector can transfer data through other interfaces. For example, DisplayPort, HDMI and the same Thunderbolt. To simplify it further, imagine an analogy. There is some kind of pipe through which water flows. But inside the pipe can (this is not necessary) be divided into two or more segments. Water will flow through one, milk through the other, and wine through the third. You can choose drinks to your taste.

This is roughly how USB-C works. In most cases, there is no support for alternative modes as it is unnecessary, but if necessary, manufacturers use this port feature.

So, if a device has a Thunderbolt 3 “port,” this means that it actually has a USB-C port, which, among other things, also supports the TB3 interface. In general, do not confuse the concepts of interface and port.

Whatever generation the USB-C port is, it will not necessarily support TB3. Manufacturers always (or almost always) separately note support for TB3, since this is a very significant distinguishing feature.

It is for this reason that the same external video cards that are connected only through TB3 cannot now become a fairly mass product and certainly cannot replace mobile gaming PCs. Simply because there simply aren’t that many suitable laptops. At one time there were rumors that Intel would add a TB3 controller to its chipsets, which would greatly simplify the situation and could make the interface as widespread as USB. However, this has not happened so far. Considering recent revelations regarding the postponement of the release of 10-nanometer CPUs, I can assume that, at best, integration should be expected next year, and perhaps Intel has completely abandoned this idea due to certain reasons, which will be discussed later.

Why is it now, even without the integration of controllers into chipsets, that TB3 is not widespread? The reasons are the same: the need to pay Intel and the need to buy expensive controllers. Unfortunately, I did not find current data on the price, but according to some leaks, in total this is several tens of dollars for one device. And if in the case of expensive laptops such a markup is insignificant, then in the budget segment it is unacceptable, given that not everyone needs the TB3 itself. By the way, this is another reason. There are very few devices that use this interface exclusively. These are external video cards, all sorts of NAS and some other devices that are needed by themselves, relatively speaking, only a few.

And now, actually, the question. Is there a future for Thunderbolt 3? Just a few months ago I would have assumed that this was possible. But recently, as I already said, Intel postponed the release of new CPUs to next year. That is, in the best case, chipsets with an integrated TB3 controller will appear in about a year. And then these are still just assumptions from scratch. If this does not happen, then another option is to reduce the cost of controllers and waive license fees from Intel. About a year or a year and a half ago, Intel claimed that it was going to do this, but since then I have not heard that the company did so. Well, the fact that there are no more devices with TB3 indicates the absence of changes in this matter.

Let's move on. Last fall, the specifications for the USB 3.2 standard were adopted. It implies an increase in maximum throughput from 10 Gbit/s (for USB 3.1) to 20 Gbit/s. The first devices with USB 3.2 should appear in about a year. TB3 has a maximum throughput of 40 Gbps, but in fact there are several options for implementing the interface, which depend on the number of PCIe lanes used. In the worst case, the speed is only 15 Gbps. Thus, USB 3.2 in some cases may be even faster than TB3. Moreover, this interface is shareware, although, of course, at first the controllers will be more expensive than USB 3.1 controllers. As a result, it turns out that within a year TB3 will have a conditional alternative. Yes, USB 3.2 cannot be called a full-fledged competitor to Thunderbolt 3, but in some scenarios, as I already noted, they can be compared. And why then would Intel add a TB3 controller to its chipsets against this background?

I assume that either Intel will abandon the development of its interface altogether, or will make great efforts to promote it after the appearance of TB4.

If any of you are using Thunderbolt 3, please post your scenarios.

If you find an error, please highlight a piece of text and click Ctrl+Enter.

• Translation

Have you already bought yourself a new MacBook or MacBook Pro? Or maybe Google Pixel? You're about to get confused, thanks to these new "USB-C" ports. This simple-looking port is fraught with confusion, and blessed backwards compatibility uses different cables for different tasks. Buyers will have to choose their cable very carefully!

USB Type-C: ports and protocols

USB Type-C ports have become quite widespread, Google has started using them on its Pixel and Nexus computers and phones, Apple is using them on the 12" MacBook, and now on the new MacBook Pro. This is the physical specification for the 24-pin reversible plug and associated cables. In this article, I will refer to this physical cable and port as "USB-C" as the most commonly used term. Google reports that this port is called "USB-C" 21 million times, "USB C" 12 million times, and That's right, "USB Type-C", a total of 8.5 million times.



USB-C Compatible: Multiple protocols supported, and each layer is backwards compatible with the layers below

USB-C allows various signals to pass through:

USB 2.0 – Oddly enough, the earliest USB-C devices, including the Nokia N1, only supported USB 2.0 signals and power. Almost all new computers support at least USB 3.0, but some phones and tablets still have limitations.

USB 3.1 gen 1 – very similar to “SuperSpeed” USB 3.0, 5 Gbps serial communication for all sorts of peripherals, from hard drives to network adapters and docking stations. Backwards compatible with “SuperSpeed” USB 3.0, “Hi-Speed” USB 2.0 and even the original USB 1.x from 1996! This protocol is used by Apple in the 12″ MacBook.

USB 3.1 gen 2 – the confusingly named version doubles the bandwidth of USB peripherals to 10 Gbps. Backwards compatible with all previous USB versions. Only the newest USB-C devices support it. I wonder who came up with such a name for it.

Alternate Mode – The physical USB-C connector supports other non-USB protocols, including DisplayPort, MHL, HDMI and Thunderbolt. But not every device supports the Alternate Mode protocol, which is very confusing for buyers.

Power Delivery is not a data protocol, but USB-C allows up to 100 W of power. But again, there are two different specifications and many different configurations.

Audio Accessory Mode – A specification for use with analog audio.

The main problem with USB-C is confusion. Not every USB-C cable, port, device, and power supply will be compatible with each other, and many combinations will have to be considered. The newest, most sophisticated devices (like a MacBook Pro with Touch Bar) will support most different uses of the port, but common older devices only support USB 3.0 and, if you're lucky, Alternate Mode DisplayPort.

But that's not all. Many USB-C peripherals also have their limitations. Imagine a USB-C HDMI adapter. It can implement HDMI over USB 3.0, or it can use native Alternate Mode HDMI. It can also multiplex HDMI with Thunderbolt Alternate Mode, and even, in theory, HDMI over Thunderbolt using an external graphics chip! I was the one who promoted the idea of ​​Thunderbolt Display with a built-in GPU. And only the newest computers will support all three modes. Imagine how confused it would be for a consumer who bought a “USB-C HDMI adapter” to discover that it doesn’t work with a MacBook or Pixel or whatever?

Cable nightmare

StarTech Thunderbolt 3 USB-C Cable (40 Gbps)

Monoprice Palette Series 3.1 USB-C to USB-C with PD (10 Gbps, 100 Watts)

Monoprice Palette Series 3.0 USB-C to USB-C (5 Gbps, 15 Watts)

Monoprice Palette Series 2.0 USB-C to USB-C (480 Mbps, 2.4 Amps)

These cables look the same, but they have very different capabilities! (I think Monoprice posted one photo for two different cables)

Cable compatibility problems are even more serious. Many companies, including my favorite Monoprice, make USB-C cables of varying quality and compatibility. If you're not careful, you can limit your capabilities or even damage your devices with the wrong cable. Seriously: the wrong cable can damage your device! This shouldn't happen, but here it is.

Some cables with USB-C on both ends can only transfer 5 Gbps, others are compatible with 10 Gbps USB 3.1 gen 2. Others cannot be used for power, or are not compatible with Alternate Mode Thunderbolt. Check out the Monoprice 3.1 10 Gbps/100-Watt USB-C to USB-C, 3.0 5 Gbps/15 Watt USB-C to USB-C, and 2.0 480 Mbps/2.4 A USB-C to USB-C. Why do they even exist? Why do you need a USB-C to USB-C cable that only supports 2.0?

There are also cables with different connectors at the ends. Monoprice sells a cool USB-C to USB 3.0 10 Gbps adapter, but they also have one that supports 5 Gbps, and even the limited 480 Mbps USB 2.0. And they look almost the same. What a consumer nightmare! Monoprice incorrectly labels every 5 Gbps cable as USB 3.0 and every 10 Gbps cable as USB 3.1. On the other hand, such names are more understandable to the user than official ones.

I don't knock Monoprice. I like their cables. But their huge range of USB-C cables illustrates the incompatibility problem perfectly. Almost all manufacturers and sellers have these problems.

Thunderbolt 3

Let's move on to an even more confusing topic. Since the launch of MacBook Pro sales in 2011, Mac owners have become accustomed to the Mini DisplayPort connector, which works as both a graphics port and a data port. They're also used to plugging a Thunderbolt cable into a Mini DisplayPort only to find that nothing works.

The same experience awaits us with the new USB Type-C port:

Not all USB-C ports have the same capabilities. Many are designed only for data, some are capable of data and video, very few are capable of data, video and Thunderbolt 3!

Thunderbolt 3 requires a special cable. Although it looks exactly the same as regular USB-C!

Thunderbolt 3 devices look exactly the same as USB-C devices—regular devices with a USB-C cable are limited to speeds of 5 Gbps or less, but Thunderbolt 3 devices transfer PCI Express at 40 Gbps!

Thunderbolt 3 ports and cables must be backward compatible with USB 3.1 Type-C cables, ports, and devices. But they will work slower. Let's praise the creator for backwards compatibility. This, by the way, is a simplification. In fact, Thunderbolt 3 is an “Alternate Mode” for the cable and Type-C port, just like HDMI. But in practice, Thunderbolt 3 is a superset of USB 3.1 to USB-C, since there are no Thunderbolt 3 implementations that support only USB 2.0.

Therefore, owners of Thunderbolt 3-enabled machines must be careful when purchasing devices and cables to avoid running out of bandwidth. Most of Apple's current USB-C accessories and cables will work with the new MacBook Pro (it's backwards compatible), but may not provide full speed. And it’s even worse for owners of old 12″ Retina MacBooks, since devices with Thunderbolt 3 will not work there at all!

Because Thunderbolt 3 includes data and video, it can be easy to get confused about the compatibility of computers, cables, and devices. For example, a Thunderbolt 3 cable can support two 4K 60Hz monitors, or even a 5K monitor, while a USB-C cable is limited to one 4K monitor. It's funny that USB-C Alternate Mode does not have the same video compatibility as Thunderbolt 3. The latter supports HDMI 2.0, while USB 3.1 only supports HDMI 1.4b. But in the case of DisplayPort, USB 3.1 will have the advantage that it supports version 1.3, and not just 1.2, like Thunderbolt 3. It all depends on the implementation on a particular machine.

Apple did not create a Thunderbolt icon on the new MacBook Pro, which further confused consumers!

Note that Thunderbolt 3 cables are available in both 40 and 20 Gbps. And the MacBook Pro is not compatible with the first generation of Texas Instruments Thunderbolt 3 controllers used in many early Thunderbolt 3 devices!

My opinion

Given this insane level of "compatibility" for the new USB Type-C port, buyers will have to be very careful. While it's a good thing that the industry is moving toward simple, reliable, two-way ports for data, video, and power, this mess of devices and cables will frustrate consumers and annoy technicians.

Addition: if it’s stuck, it should work

I received a lot of criticism of the original version of the article, and it is that it doesn’t seem to be as bad as I describe. This is mostly true as long as people have USB-only Nexus phones and the like. But I think there's a problem with the many uses for this versatile cable and port.

Electronics is no longer an area of ​​interest only for geeks. Most computers, phones, tablets and peripherals are purchased by people who are not technically savvy. They will not distinguish a protocol from an interface and are not required to understand how “USB Type-C” differs from “Thunderbolt 3” or “USB 3.1”. They want to buy things, connect them, and have everything work. They judge compatibility by the shape and fit of connectors, not by specifications or logo.

Historically, the industry has been good at this. After its initial rough patches, USB has become a boon for the average user. Cables, devices, peripherals - for the most part they just work. While the experience of using USB 3, Mini USB, Micro USB and high power chargers is not ideal, the user expectation of “it fits means it works” still holds true for USB today. I myself am using a string of cheap USB cables right now. And the reason is that USB was both a cable and a protocol. Power aside (how many iPads are slowly charged by iPhone cubes?), USB worked because USB is USB.

And now there is a “universal” cable that can become the only port on the device. Data, video, power – there’s just one USB Type-C port for everything. And Intel has shifted into higher gear by adding an entirely separate world of data and video support, Thunderbolt 3. It's unrealistic to expect all ports, cables, and devices to work correctly with each other, especially when it's much cheaper to make a USB 3.1 gen 1 device or cable. or even USB 2.0.

From now on (since Thunderbolt 3 devices started being sold), we have a port that does not meet user expectations. The cables are not compatible, the devices do not support any peripherals, although the ports look the same. It's a nightmare: a consumer will pull the wrong cable out of a drawer, magazine, or backpack, and assume the device or charger is broken when it won't work. We will face disappointments, returns and confused tech support.

It's an old compatibility story. We're improving compatibility to raise consumer expectations that everything will just work. But USB Type-C will never just work because USB-C is too many things at once. And it's a nightmare.

Thunderbolt is an input/output interface found primarily on Apple computers and laptops, promising incredible throughput and data transfer speeds. On the other hand, the universal standard USB 3.0, which represents a huge step forward over its predecessor, is backward compatible, and is available in a wide range. In this article, I will describe the capabilities of both of these devices and try to conclude which one is better.

Do you know that?
The Thunderbolt interface was originally designed to work with fiber optic cables, and was previously called Light Peak.

The Universal Serial Bus (USB) needs no introduction. Since USB ports and connectors first appeared on PCs in 1995, they have come a long way and are now ubiquitous. Every computer and laptop comes with a range of USB ports. Devices such as USB hubs, which allow users to access even more ports, have become widespread. USB ports are even found on non-traditional electronic devices such as televisions, DVD players and stereo systems. Now that all kinds of electronic devices including mobile phones and cameras also use mini or micro USB interface for charging or data transfer, calling this technology "universal" is more than apt.

On the other hand, "Thunderbolt" is a term whose popularity is largely limited to Apple products. Although this technology, which was conceived and developed by Intel, is not as widely used as the USB interface, this fact in no way reflects its ability or performance. In fact, no amount of praise can do justice to the unrivaled bandwidth and data transfer speeds of the Thunderbolt interface.

It may be surprising that the newest standard, Thunderbolt 2.0, which has so much potential, hasn't fared as well as its competitor, USB 3.0.

Thunderbolt interface vs USB 3.0

Main technical characteristics

♦ USB 3.0, a high-speed interface with no cable length restrictions, improved power management, and backward compatibility.

♦ USB 3.0 achieves "Super Speed" with the help of additional parallel data buses. This accessory not only increases system throughput, but it also provides full-duplex data transmission (that is, data can be transmitted in both directions simultaneously). Both of these factors contribute to USB 3.0 achieving data transfer speeds much higher than USB 2.0.

♦ Energy efficiency is a highlight, USB 3.0 has the ability to deliver one and a half times more power than its predecessors to optimized devices (such as those that use USB charging ports). In addition, ports can switch to a power-saving mode when not in use.

♦ Compared to USB 2.0, this standard is better suited for any application that requires high bandwidth, from high-capacity storage devices to video transmission over DVI.

Thunderbolt

♦ Thunderbolt, combines PCI Express, a high speed, two-way serial data connection standard, and DisplayPort, which is used to connect to a display device (the technology is the same as HDMI, except that it is compatible with VGA and similar older video formats ) into a single port/connector system.

♦ This means that it supports high-speed data transfer between devices, has the ability to function as an Ethernet link (with an adapter, of course), supports hot plugging (the ability to connect and disconnect equipment without rebooting the system), and can also be used to connect display devices , such as monitors, including those with 4K HD resolution.

♦ Thanks to its high bandwidth, one port can be used to connect up to six high-speed compatible hardware devices, without any loss of bandwidth.

♦ On top of all this, it has the ability to provide up to 10W of power.

Winner: In terms of features and specifications, USB 3.0 and Thunderbolt seem to be very promising and I have no choice but to call it a tie.

Speed

**Note: The speeds mentioned in this section are theoretical or maximum values. The actual data transfer rate may be much lower.

♦ USB 3.0 has a maximum speed of almost 5 GB/sec, which means a channel bandwidth of 675 MB per second, about ten times faster than its predecessor, USB 2.0.

♦ This capability makes it ideal for use in scenarios that require higher throughput, including RAID storage devices, which was previously unimaginable.

Thunderbolt

♦ Unlike USB 3.0, which limits data transfer to just one channel, Thunderbolt has four independent channels, meaning that if more than one device is connected, each of them will be provided with a maximum data transfer rate of 10 GB/sec.

♦ On already released (and available in a number of recent Mac/MacBook devices) Thunderbolt 2 - this technology has the ability to offer a maximum speed of 20 GB/sec, which is four times faster than USB 3.0, and 2 times faster than USB 3.1. This phenomenal speed is achieved by combining two bidirectional data lanes with the same bandwidth of one Thunderbolt channel into one channel with twice the bandwidth.

Winner: I have no doubt about who is superior in this regard; Thunderbolt is the clear winner in terms of speed.

Price

**Note: prices shown in this section are relative and subject to change.

♦ The biggest factor in the popularity of USB 3.0 is its low cost. Also, USB ports are already installed by manufacturers on every Intel and AMD chipset.

♦ Being a universal standard, almost every device comes with a USB connector, and therefore cables of all varieties, including mini and micro USB connectors, are easily available at low prices.

♦ The approximate cost of any universal USB 3.0 compatible external hard drive with 1 TB capacity starts from USD 60 (4,000 rubles at the time of writing this article).

Thunderbolt

♦ It costs USD 60 to include just one Thunderbolt port on any PCB.

♦ Computers that are equipped with Thunderbolt ports are quite expensive. Most of Apple's recently released desktop devices that feature these ports fall in the USD 1,000 to 4,000 price range.

♦ In fact, to use these Thunderbolt ports, you need to purchase compatible peripherals in addition to the computer itself. And they don't come cheap either. The 27-inch Apple Thunderbolt Monitor, for example, costs USD 999.

♦ What is a port without cables, connectors and adapters? When a 2-meter cable costs USD 39 and a Gigabit Ethernet adapter costs USD 29, it becomes clear that investing in Thunderbolt can be very expensive.

Winner: Taking advantage of its versatility that is nearly impossible to replicate, USB 3.0 is the clear winner in this category.

Compatibility

USB 3.0 interface

♦ USB 3.0 and its predecessor USB 2.0, fully compatible interfaces. This means that if there is a mismatch between the port and the standard cable, data transmission takes place according to the lower standard.

♦ In general, the USB interface is present in almost every electronic device that exists today. Additionally, USB 3.0 has expanded the usability of USB on a larger scale. Thanks to its design, which improves its energy efficiency, the USB platform can now be used to connect high-power devices such as monitor displays, as well as in applications requiring high data transfer rates, such as video and audio interfaces and Blu-Ray recordings.

Thunderbolt

♦ Thunderbolt and Thunderbolt 2 technology are compatible with each other in the same manner that USB 3.0 is compatible with all its previous versions. Thunderbolt cables are also interchangeable. The computer, interface, and peripheral (and all devices in the daisy chain) must support Thunderbolt 2.0 for maximum speeds to be achieved.

♦ Any monitor that supports the mini-DisplayPort standard can be directly connected to a computer equipped with a Thunderbolt port. However, a cable with a mini DisplayPort connector cannot be used with a Thunderbolt peripheral.

♦ Since Thunderbolt technology is not widely used, it is limited to computers and peripherals that support the protocol. To connect other monitors that support other standards such as VGA, DVI and HDMI, etc., to the Thunderbolt port, adapters with Thunderbolt ports for the corresponding format are required.

♦ The corresponding adapters are not always easy to find, not to mention their cost, and if you want to connect, for example, an Xbox or PlayStation to an Apple Thunderbolt monitor, you will need completely different adapters manufactured by third-party companies.

Winner: Thanks to its unrivaled ubiquity, USB 3.0 wins by a landslide.

My verdict

Before publishing my conclusion, I would like to draw your attention to the following facts.

Thunderbolt, in terms of speed, technology, design and published endurance testing, is a far superior and futuristic I/O standard that truly deserves the title of "Best Interface". It was so ahead of its time that many "compatible" devices available today are not even capable of taking full advantage of Thunderbolt and Thunderbolt 2.0 ports. However, in terms of audience reach, Thunderbolt falls short of USB. Apart from specific peripherals, Thunderbolt can only be used to connect a limited number of alternative interface standards, even when using adapters. The cost factors are of course interrelated, and that is why the Thunderbolt has only limited use, although its potential is enormous.

While USB 3.0 can't match Thunderbolt's speed levels, it does offer a very noticeable improvement over the previously common standard! USB 3.1 already has excellent speed, not to mention its cross-compatibility with a number of other standard interfaces via adapters, and hence consumers are hesitant to switch to other standards, even if they may perform better.

I believe that although the maximum data transfer speed that USB 3.0 offers is not a huge figure, it is enough to greatly increase its range of applications, and with additional features such as power saving, and of course its popularity , USB 3.0 is the best interface nowadays. As for Thunderbolt, only time will tell if it's worth the investment.

I hope you enjoyed my comparison between these two of the world's largest communication interface devices and that you were able to decide which one is most suitable for you. If you have anything to add to my comparison, write in the comments.

1. iMac Pro and MacBook Pro 15-inch can connect up to four 4K monitors or two 5K monitors; for Mac mini - up to three 4K monitors or one 5K monitor; for iMac, MacBook Air and MacBook Pro 13 inches - up to two 4K monitors or one 5K monitor; for MacBook - one 4K monitor.
2. Testing conducted by Apple in October 2016 using preproduction 2.9 GHz quad-core Intel Core i7-based 15-inch MacBook Pro units, 1 TB flash storage, and 16 GB RAM. Files were copied from the MacBook Pro's built-in flash storage to a reference striped RAID array consisting of two LaCie Bolt SSDs. Audio transfer tests used M4A audio files purchased from the iTunes Store. Photo transfer tests used photos taken on an iPhone 7 Plus. When testing video transmission, we used video recordings with a resolution of 1080p and a frequency of 30 fps, shot on an iPhone 7 Plus. MacBook Pro continuously monitors temperature and energy levels and can adjust performance as needed to maintain optimal operating conditions.

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