With Thunderbolt ports becoming more common in laptops, a Thunderbolt dock can be a critical accessory. Think of the Thunderbolt dock as a more powerful, high-speed alternative to a USB-C hub, adding I/O expansion to your laptop in the form of extra ports for mice, keyboards, external drives, SD cards, and, most importantly, displays. It can even charge your laptop and smartphone!
Simply put, laptops are slimming down. Though cheaper laptops still include microUSB ports, HDMI, SD card slots, and more, premium laptops are opting for the “clean” look, and are pushing all of these legacy ports onto external devices — the choice here is between a USB-C hub and a Thunderbolt dock.
The difference? Price and bandwidth. USB-C hubs are far cheaper, but they offer far less bandwidth, too. That specifically matters where displays are concerned, but also external hard drives and other storage devices. While a USB-C hub can support a single 4K display, often at an eye-wearying 30Hz refresh rate, Thunderbolt hubs can support up to two 4K displays at a comfortable 60Hz. They’re also much more likely to future-proof your PC. You can also use Thunderbolt to enable an external GPU for your PC.
If your laptop includes a Thunderbolt port, chances are it supports the Thunderbolt 3 or Thunderbolt 4 standard, both of which provide 40Gbps. Intel helped launch the updated Thunderbolt 4 specification in July 2020 as part of its 11th-gen “Tiger Lake” Core laptops, and the specification has become more popular on productivity laptops. The bandwidth behind Thunderbolt 4 is enough to drive those displays and shuttle data back and forth between peripherals without causing your display to flicker or your video stream to stutter.
What’s the difference between Thunderbolt 3, Thunderbolt 4, and USB4? The simple answer is that they’re all similar. The longer answer, explaining the differences, may be found within our Thunderbolt buying guide below our recommendations. If you want to learn more about the benefits of a Thunderbolt dock, what to look for when buying one, or how to know whether your laptop will support one, look here as well.
We’ve updated our picks as of November 2021, adding the latest Plugable Thunderbolt dock to our tests. More updates will be coming soon.
The best budget Thunderbolt docks
No surprise—budget usually means basic. But that’s okay! You’ll still find a mix of common ports, and usually two monitor outputs—either HDMI or DisplayPort. Make sure you have the right video cable, or be prepared to buy one.
Also, some budget Thunderbolt hubs are bus-powered, meaning that while they won’t require an external charger (which makes them more portable), they probably won’t be able to deliver enough power to charge a phone if your laptop is not plugged in. The price makes them worth a second look, though.
IOgear Thunderbolt 3 Travel Dock (GTD300)
Although it’s listed as a travel dock, the IOgear GTD300 serves as a very good regular work companion. The Thunderbolt 3 dock is bus-powered, however, which means you’ll want your laptop to be plugged in for best results, though the hub itself doesn’t require its own charger.
IOgear’s plastic dock measures just 2.2 x 0.91 x 4.06 inches, and is among the smallest we’ve tested, so it neatly fits into a backpack for travel. On its underside, a green plastic shell conceals a nook to store the dock’s short, 5-inch cord when not in use.
Ports are minimal: one HDMI 2.0 port, one DisplayPort 1.2 port, one 5Gbps USB-A port, and gigabit ethernet port. If you’re okay using the USB port for a mouse or keyboard, rather than for high-speed external storage, the GTD300 will suit you fine. (Of course, we’d have preferred a 10Gbps port, at least.)
Some of Amazon’s customer reviews are slightly confusing: In our experience the ethernet port worked as expected, as did the USB-A port. Perhaps because of the small form factor, the GTD300 gets noticeably hot, but not uncomfortably so in our opinion.
Belkin Thunderbolt 3 Dock Core
Belkin’s Thunderbolt 3 Dock Core arrived in bare-bones packaging, and the product is equally unadorned: It’s a smartly designed “powered” Thunderbolt 3 travel dock.
At a nearly square 5.2 x 6.5 x 1.5 inches, the Thunderbolt Dock Core black doesn’t take up much room, and the included 8-inch Thunderbolt 3 cord provides ample length for flexibility. Ports are adequately spaced out around the flat, black plastic cube, with HDMI 2.0 and DisplayPort 1.4 ports providing a stable 4K/60Hz experience to both of my 4K displays. There’s gigabit ethernet and a 3.5mm audio jack, but good luck telling the USB 3.1 and USB 2.0 Type A ports apart—they’re not labeled.
There’s one catch: The additional USB-C port on the Dock is a vanilla USB-C port that needs to be connected to a 60W charger to power the dock—which isn’t supplied. That’s fine if your laptop charges with a USB-C charger; if it doesn’t, you’ll need to buy one. That means extra expense and something else to carry.
Save for the irritating lack of labels on the USB-A ports, the Dock Core worked as expected, with solid performance. The plastic shell never warmed to worrisome levels.
OWC Thunderbolt Hub (OWCTB4HUB5P)
Other World Computing (OWC) specializes in Mac products, where Thunderbolt-powered displays are more common than the Windows world. This is important, since the relatively tiny OWCTB4HUB5P offers just a 10Gbps USB 3.2 Type A port, a Kensington lock, and three Thunderbolt 3 ports.
Designing a Thunderbolt 4 dock with three Thunderbolt 3 ports makes sense if you’re directly connecting a Thunderbolt display (something that in 2021 we don’t advise doing) or a direct-attached Thunderbolt device. You can daisy-chain up to five devices. But if you were considering buying the OWC Hub to connect to another Thunderbolt dock—which would drastically expand your I/O options further—beware. While the OWC Hub can drive two 4K displays at 60Hz, interjecting another dock limits the output to just one, our testing and OWC support staff confirms.
That’s unfortunate, because the tiny (4.7in x 2.9in. x .7in.) metallic hub fits neatly on your desk, though with a 110W power brick that dwarfs it. At 7.4 oz, it’s definitely portable. The Hub supplies 60W to the laptop, and 15W to downstream devices —even if the host PC is sleeping. I/O rates were consistent across all of the ports, even while other ports were active. OWC’s Thunderbolt Hub became fairly warm while using it, though not uncomfortably so. The Thunderbolt 4 cable length is enormous, at about 2.5 feet long.
This is a specialized Thunderbolt design that we’d recommend most pass over. But for those who have committed to a Thunderbolt future, the OWC Thunderbolt Hub makes more sense.
The best full-featured Thunderbolt docks
Most of the “full-featured” Thunderbolt docks were originally designed for content creators, specifically the Mac market. In this class, powered docks are the norm, shipping with the sort of sizeable power bricks normally associated with gaming laptops. Unlike our budget options, these docks are truly desk-bound.
Expect the 40Gbps bandwidth common to all Thunderbolt 3 docks to be shared among a surfeit of ports, including multiple USB-A ports, a USB-C port or two, SD card slots, and more. Audio jacks are common, and you may even find an external Thunderbolt 3 port as well for daisy-chaining additional devices. All of those ports take up space, so a model that can be positioned on its edge or vertically is better for cramped work surfaces.
We will note that Plugable’s docks, though our favorite, quickly sell out, possibly due to supply-chain issues. If you’re in the market for a Thunderbolt dock, buy it quickly!
Plugable TBT3-UDZ Thunderbolt 3 Dock
Plugable’s TBT3-UDZ is simply one of the best Thunderbolt 3 docks we’ve tested, though it’s also one of the most expensive, too. With a boatload of ports, including options for using DisplayPort or HDMI for both displays, the TBT3-UDZ offers flexibility and then some. There’s even a sturdy stand to mount it vertically on your desk.
On the front, the TBT3-UDZ includes a 10Gbps USB-C and a 10Gbps USB-A (USB 3.1) port, microSD and SD card slots, plus a headphone jack. On the rear, five USB-A (USB 3.0 ports) and gigabit ethernet complement a pair of DisplayPort 1.4 ports and HDMI 2.0 ports. (It’s all based on Intel’s Titan Ridge chipset.) A 29-inch 40Gbps Thunderbolt 3 cable connects the dock to your laptop, and is capable of delivering 96W of power over a 2.6-foot Thunderbolt 3 cable. Naturally, this is a powered dock, with a hefty 170W (!) charger.
Performance was excellent, driving both 4K displays at 60Hz, and transferring our test file at close to peak speeds while simultaneously playing back two 4K/60Hz videos on both displays over Ethernet. The attractive gun-metal chassis never warmed uncomfortably, though it’s a whopping 4.1 pounds—probably heavier than the laptops it’s driving. The extra weight, plus the chassis stand, keeps the TBT3-UDZ rock-solid while in its vertical, space-saving orientation. It measures about 8 inches long/high by 3.75 inches wide, and an inch thick.
A two-year warranty covering limited parts and labor is included.
Plugable TBT3-UDC3 Thunderbolt 3 Dock
Plugable’s TBT3-UDC3 is a smaller, less expensive version of the TBT3-UDZ, with less I/O flexibility but more focus. The dock includes a pair of USB-A 5Gbps ports on the front for a mouse and keyboard, and then a second USB-A (10Gbps) port on the back. A pair of two 10Gbps USB-C ports sit alongside it for further expansion. There’s Gigabit Ethernet, too. Smartly, Plugable includes one HDMI 2.0 port and a DisplayPort 1.4 port for display connections, plus an HDMI-to-DisplayPort dongle in the box in case you own two HDMI displays.
A 2.6-foot Thunderbolt 3 cable supplies 96W of power to a laptop, which is excellent.
Performance was on par with the TBT-UDC3, with very little heat emitted from the dock. On one occasion the dock stopped working, but resumed working a second time when we plugged it in a week or so later. This seems like an otherwise excellent dock, but we’ve slightly lowered the rating because of this. Plugable includes a two-year warranty in case you receive a bad unit.
CalDigit Thunderbolt Station 3 Plus (CalDigit TS3 Plus)
CalDigit’s Thunderbolt Station 3 Plus is one of the most popular Thunderbolt 3 docks available, and it’s easy to see why: a space-saving vertical orientation, 87W charging, gobs of available ports, and even niceties like a S/PDIF optical connection and an external Thunderbolt jack for daisy-chaining devices.
The TS3 Plus measures 5.15 x 3.87 x 1.57 in., and weighs 1.04 pounds. Though it lacks a supporting stand, it rested easily in a vertical position. CalDigit includes small rubber feet for positioning the aluminum dock in an horizontal orientation.
Port selection includes: two Thunderbolt 3 ports (one from the laptop, and one for an external connection), and a single DisplayPort 1.2 port. That’s ideal for a single 4K display, but awkward for two. The TS3 Plus includes 1 full-sized SD (SD 4.0 UHS-II) card reader, the S/PDIF port, gigabit ethernet, and two 3.5mm audio jacks—one in, one out. Five USB Type A ports are also included (all 5Gbps USB 3.1 Gen 1) and two USB-C ports (one 5Gbps port, and one 10Gbps port).
To enable two 4K/60 displays, you’ll need a second USB-C dongle running off either the Thunderbolt or USB-C dock—or a forward-looking display with a built-in Thunderbolt/USB-C connector. These are still rare in the Windows world.
Daisy-chaining the Thunderbolt port to enable a second monitor worked fine, though the connection dropped momentarily on both displays when playing back video on both displays and transferring files. Otherwise, high-bandwidth video playback went completely smoothly. The external audio jack also didn’t work initially, but did on a subsequent retry. CalDigit’s TS3 Plus barely warmed under load.
Other Thunderbolt docks we tested
Your Thunderbolt dock choices extend far beyond what we’ve recommended. Hubs mix and match different port types, and different form factors. Pay attention to our ratings, prices, and the quirks of each to find an option that fits your specific needs.
Thunderbolt 3 Mini Dock (Dual HDMI 2.0) (TB3-MiniDock-HM)
Out of the box, the CalDigit Thunderbolt 3 Mini Dock (Dual HDMI 2.) seems ideal for a purpose-built, bus-powered Thunderbolt dock: rather inexpensive, with just the ports you’ll need and not much else.
The version we reviewed ships with gigabit ethernet, a pair of USB Type-A ports (USB 3 and USB 2) and two HDMI 2.0 ports. A shortish 5.3-inch Thunderbolt 3 cable connects the bus-powered TB3-MiniDock-HM to your laptop. Remember, “bus-powered” means that you don’t need a charging brick, saving space.
Our test laptop began unexpectedly reporting glitches, however, including visual errors on both displays and the inability of the laptop to read USB drives or connect to a USB mouse—until we discovered that the power cable had worked loose. CalDigit diagnosed the problem as our laptop’s inability to supply the requisite 15W of power for the Mini Dock to function appropriately. (The Mini Dock does not include a charging port, and we’ve seen other users complain about the USB-A issue.) The Mini Dock again worked when we attached the laptop’s charger, but subsequently failed to recognize an external USB drive. It seems like not enough power is consistently passing through the USB-A ports, based on our tests with a USB-C power meter. We tested the dock on a second Thunderbolt-powered laptop and received the same result.
Performance-wise, the Thunderbolt 3 Mini Dock performed well, though with numerous frames dropped on our two 4K/60Hz test videos. Heat was never an issue.
OWC Thunderbolt Dock (OWCTB4DOCK)
The big brother to OWC’s Thunderbolt Hub, the OWC Thunderbolt Dock provides three Thunderbolt 3 ports for Thunderbolt devices, plus three USB-A 10Gbps ports, one USB-A 2.0 charging port, an SD (UHS-II) card slot, gigabit Ethernet, and an audio jack.
Like its smaller sibling, this is a specialty dock is designed for those who have invested in Thunderbolt displays and other Thunderbolt devices. There are no external display connections besides the Thunderbolt interface. The Dock measures 7.8in. x 2.9in. x 1.0in. and 14.1oz. The included Thunderbolt 4 cable measures about 2.5 feet.
Like the OWC Thunderbolt Hub, the Dock supports direct connections to Thunderbolt displays and devices, including a pair of 4K/60 displays. (The Dock supports DisplayPort 1.4.) If you connect another Thunderbolt dock to one of the Thunderbolt 3 outputs, however, only one 4K/60 display will be enabled. Directly connected, a Thunderbolt 4 drive wrote data at 1,221 MB/s and read at 2,292 MB/s. Connected to the Dock, it wrote at 1027 MB/s and wrote at 2210MB/s. An SD card placed inside the Dock read and wrote data at speeds comparable to an SD card slot built into Microsoft’s Surface Book 4 laptop.
OWC says that the Dock supplies up to 90W for charging the host laptop. OWC doesn’t define the charging capabilities of the “charging” USB 2.0 Type A port, but we measured it at about 7W, enough to charge, but not fast-charge, a OnePlus smartphone. The Dock remained absolutely cool to the touch under load.
Thunderbolt dock buyer’s guide
Two laptops, both with USB-C ports, and both with lightning-bolt symbols. Which laptop offers Thunderbolt? The top one, though it can be difficult to tell. Consulting the manufacturing specifications is your safest bet.
If you’re on the fence about whether a Thunderbolt dock is right for you, knowing the answers to the following questions could help you.
How do I know if my laptop has Thunderbolt?
The short answer: Look at the laptop’s published specifications to be sure. A Thunderbolt port may look indistinguishable from a USB-C port, since they both use the same physical USB-C connection. Put another way, all Thunderbolt ports are USB-C, but not all USB-C ports are Thunderbolt-equipped.
Thunderbolt ports are supposed to have a small lightning-bolt icon to identify them. But some laptop makers use a similar lightning-bolt icon to indicate that a USB-C port can be used for charging your phone, and not for Thunderbolt. Laptop makers sometimes don’t want to clutter the clean lines of their products by adding additional logos, it seems.
Adding to the confusion, you may also see USB-C hubs marketed as “Thunderbolt compatible.” That’s true. You can plug a Thunderbolt dock into a non-Thunderbolt, generic USB-C port. But it will be limited by the available bandwidth that the port provides, so it’s somewhat deceptive in that regard.
A Thunderbolt 3 “compatible” dock is not a true Thunderbolt dock, but a USB-C hub. The tipoff here is the 5Gbps throughput.
How fast is Thunderbolt?
Most USB-C ports are built on the second-generation USB 3.1 data-transfer standard, which transfers data at 10Gbps. Most Thunderbolt 3 ports, the most common standard, transfer data at up to 40Gbps. Thunderbolt 4 differs slightly in that it supports a theoretical maximum of 32Gbps where data transfers are concerned, specifically for external storage devices.
There are somewhat rare exceptions: A new USB 3.2 Gen 2X2 spec can pair two 10Gbps channels together, creating an aggregate 20Gbps hub. And while the vast majority of Thunderbolt 3-equipped laptops are designed with four PCIe lanes for a total of 40Gbps, some laptops only ship with two PCIe lanes for a total of 20Gbps. (A Dell support page, for example, details its four-lane and two-lane laptops.) Essentially, a 20Gbps connection should be enough for a single 4K monitor running at 60Hz, with a bit of extra bandwidth for other data transfers among connected peripherals.
What’s the difference between Thunderbolt 3, Thunderbolt 4, and USB4?
The short answer: Not that much, and we consider Thunderbolt 3 docks and Thunderbolt 4 docks to be functionally equivalent for most users. The longer answer, which we’ll describe below, is that there are differences, and parsing the nuances can be confusing. Think of Thunderbolt 4 as the more restrictive version of Thunderbolt 3, with little room for any gotchas.
Essentially, Thunderbolt 3 and Thunderbolt 4 allow up to 40Gbps maximum bandwidth, enough for two 4K/60 displays. “Up to” is the key phrase: Thunderbolt 3 is only required to support a 10Gbps connection, allowing for a single external 4K display (a 16 Gbps PCIe connection, paired with USB3.2). Most manufacturers go beyond this, however, and our recommended docks support the full specification (and two 4K displays) unless noted. Thunderbolt 3 also supports a slower (16Gbps) PCIe connection for connecting to external storage. Unless you’re editing video or using an external GPU, this probably won’t matter.
Thunderbolt 4 doesn’t allow for any leeway — you’re getting a full-fledged 40Gbps connection (32 Gbps PCIe + USB 3.2), no questions asked. For external storage, Thunderbolt 4 supports 32 Gbps of data transfer — again, this really only matters for video, external GPU connections, or possibly games. Thunderbolt 4 supports “wake on sleep” from an external keyboard or mouse, which allows you to tap your external keyboard or wiggle your mouse to wake your PC up, which is handy. Thunderbolt 4 allows for longer cables and more Thunderbolt ports on laptops, too.
USB4 is essentially a subset of Thunderbolt 4, mainly designed as an an I/O specification. USB4 can only support one display, and manufacturers can choose whether it supports a 20Gbps connection or a 40Gbps connection, according to Thunderbolt dock designer Plugable. As a subset of Thunderbolt 4, a USB4 device will run just fine plugged into a Thunderbolt 4 port. But a Thunderbolt 4 device may not work as expected when plugged into what is specifically a USB4 port. Don’t worry about this too much, as it’s rare to see a USB4 hub. Instead, most hubs and docks are marketed as Thunderbolt 4, while most devices (like an external SSD) are designed around USB4.
Note that Thunderbolt 3 and 4 require at least 15W to power devices plugged into the Thunderbolt port, such as a bus-powered hard drive. USB4 requires just half that.
Device maker Anker has a nice summary of all of the technical features associated with Thunderbolt 3, Thunderbolt 4, and USB4, if you really want to get into the fine distinctions.
Thunderbolt dock and I/O hub designer Anker provided this summary of the differences between Thunderbolt 3 and Thunderbolt 4.
Virtually every Thunderbolt device will ship with its own cable. We’d recommend that you use Thunderbolt 3 cables with Thunderbolt 3 products, and Thunderbolt 4 cables with Thunderbolt 4 products.
The vast majority of Thunderbolt docks should include a Thunderbolt cable like this one, which indicates that it’s specified for Thunderbolt 3.
What to look for in a Thunderbolt dock
Ports, cables, peripherals: Those are the three major considerations when buying a Thunderbolt dock.
We’re beginning to see the Thunderbolt dock market break down into a few different ways. First, there’s the budget versus full-featured docks we’ve highlighted above. But you also may see something similar to the old USB hubs of old, too: Devices that take Thunderbolt in and then provide several USB-C (including Thunderbolt) ports out. There are a small number of displays with Thunderbolt inputs, which can be plugged directly into these hubs. Do you have an existing cheap USB-C dongle? You can certainly plug that in into a Thunderbolt dock and add even more I/O functionality.
Basically, consider what you’ll want to plug into the dock as a guide for buying one. We prefer devices with ports built in (such as HDMI, USB-A, and so on) as the USB-C device ecosystem is still in its infancy. But ask yourself some questions. Do you want a basic Thunderbolt dock, with just a pair of HDMI ports for connecting two displays? Does an SD card slot matter? How many USB Type A peripherals do you plan to attach? Do you want to use the Thunderbolt cable to charge your laptop, too?
Cables can be an unexpectedly important consideration, too. Virtually every dock ships with a Thunderbolt cable. But consider the displays you own (typically HDMI or DisplayPort) and consider whether the dock will accommodate them.
Powered Thunderbolt docks, especially those that power your laptop, can ship with some pretty sizeable power bricks.
Check your laptop’s power supply. Does it plug into your laptop via USB-C? If so, a Thunderbolt dock will likely power it. You’ll need to understand how the dock supplies power, though. Check your laptop’s charger to learn how much power it supplies, and how much the dock will need to supply to replace it. If your laptop or devices aren’t receiving enough power, you may see a warning pop up.
A “bus-powered” dock won’t come with an external charger in the package, saving some cost, space, and power concerns. A dock with “power delivery” will supply its own power and charge your laptop and/or a phone via your laptop’s existing USB-C charger. (Chances are that it won’t offer the quick-charging capabilities premium smartphones offer, though.) The more power your dock supplies, the greater the ability to charge your laptop and any bus-powered devices. This is a gotcha most people don’t think about, so if you plan to connect several bus-powered hard drives or SSDs, buy a dock with a hefty power supply. (USB keys, on the other hand, require tiny amounts of power. Don’t worry about these.)
There’s one more consideration: the length of the Thunderbolt cable between your laptop and the dock itself. You may have noticed or heard about USB-C ports wearing out on smartphones; a loose or wobbly connector on Thunderbolt docks can cause monitors to unexpectedly flicker or lose connection. Consider how much tension will be put on a cable. A Thunderbolt dock that’s dangling from a Thunderbolt port will stress the physical connector. You don’t want that!
If you’re a Mac user who has stumbled across this article, welcome. But please be aware that early Apple MacBook Pros powered by Intel silicon supported up to two 4K displays. The first MacBook Pros powered by the Apple M1 chip only support a single 4K display. Many Mac users have recently left negative reviews on Thunderbolt docks on shopping sites because of this. Buy a PC!
How we tested
We’re working from the premise that you’re buying a Thunderbolt dock for its unique ability to connect to two 4K monitors at 60Hz. Lower resolutions should be much easier to run successfully. Our first test simply connected each dock to a pair of 4K/60Hz displays, each of which could accept DisplayPort and HDMI cabling, and made sure there were no visual artifacts at 60Hz resolution.
Second, we checked to see whether the available ports delivered the bandwidth we’d expect, connecting them to an external SSD and transferring a collection of test files over the Thunderbolt cable and port. We also used AJA’s System Test tool to double-check our numbers and test whether read and write speeds were consistent.
Finally, we spot-checked the available power draw of the hubs and ports with a USB power meter, as well as simply connecting them to bus-powered devices to see if they could deliver enough power to allow them to operate. Here, we discovered that one of our testing laptops didn’t supply enough power running on battery to power a bus-powered Thunderbolt dock, so we enlisted a second, different laptop as a backup.
This story was updated on November 4, 2021 with new information and product recommendations.
As PCWorld’s senior editor, Mark focuses on Microsoft news and chip technology, among other beats. He has formerly written for PCMag, BYTE, Slashdot, eWEEK, and ReadWrite.
