CalDigit TS4 Review: When a USB-C Hub Is No Longer Enough
Eighteen ports and 98 W of charging. The case for a Thunderbolt dock, and the case against buying one you do not need.
There is a point at which a USB-C hub stops being enough. You add a second monitor, a wired network, an SD card workflow and a laptop that wants charging, and a bus-powered dongle with seven ports runs out of both connections and electricity at the same time. The CalDigit TS4 is what you buy next, and it is priced accordingly.
This is a research-based buying guide, not a hands-on test. It is built from CalDigit’s published specification, with sources at the end. Read our review standards.
The short answer
Buy it if one cable has to run your entire desk. Eighteen ports, 98 W of laptop charging, 2.5-gigabit ethernet and proper UHS-II card readers, with no drivers on either macOS or Windows.
Do not buy it if you need three or four ports and some charging. A good USB-C hub does that for a fraction of the money, and most of the TS4’s value sits in capabilities you would never reach.
What 18 ports actually consists of
| Port | Count | Notes |
|---|---|---|
| Thunderbolt 4 / USB4 | 3 | 40 Gb/s. One is the host port; two are downstream at 15 W each |
| USB-A | 5 | 10 Gb/s, 7.5 W each |
| USB-C | 3 | 10 Gb/s. One front port delivers 20 W for fast accessory charging |
| DisplayPort 1.4 | 1 | Full size, no adapter needed |
| Ethernet | 1 | 2.5 GbE |
| SD card | 1 | UHS-II, SD 4.0 |
| microSD card | 1 | UHS-II, SD 4.0 |
| Audio out | 2 | One front, one rear |
| Audio in | 1 | Rear, for a microphone |
The power figures, which matter more than the count
Ports are easy to advertise. What separates a dock from a hub is whether it can feed everything at once.
- Host port: up to 98 W — enough for most 14 and 16-inch laptops at full load, not only at idle
- Each downstream Thunderbolt port: 15 W
- Front USB-C: 20 W, which is phone-fast-charge territory
- Remaining USB-C and all USB-A: 7.5 W each
Displays: read this before you buy
Dual-display support on a Thunderbolt dock is where most buyers get caught out, and the rule is set by your computer, not by the dock.
The TS4 has a full-size DisplayPort 1.4 output plus two downstream Thunderbolt 4 ports that can each drive a display. On a Windows laptop with Thunderbolt 4, that gives you native dual monitors. On Apple Silicon, the base M-series chips support only one external display over Thunderbolt regardless of what the dock offers — that is a limitation of the Mac, and no dock works around it without DisplayLink software.
The card readers are a real differentiator
Most docks include an SD slot as a checkbox. The TS4 includes SD and microSD readers that are both UHS-II — a genuinely faster interface with a second row of pins, capable of several times the throughput of the UHS-I readers found on cheaper hardware.
If you shoot photos or video and offload cards regularly, this alone removes a separate reader from the desk and saves real time on every transfer. If you never touch a memory card, it is two slots you will never use.
2.5 GbE, and whether it does anything for you
The ethernet port runs at 2.5 gigabit, two and a half times standard gigabit. Worth being honest about when that matters:
- It helps if you move large files to a NAS, work from network storage, or have a multi-gigabit internet connection and a router that supports it
- It does nothing if your internet is slower than a gigabit and your router only has gigabit ports — you will run at gigabit, exactly like a cheaper dock
Most home setups are in the second group today. It is a future-proofing feature, and it is fair to value it as one rather than as an immediate gain.
Strengths and compromises
What it does well
- 98 W host charging, the highest on a Thunderbolt 4 dock
- Eighteen ports, including five USB-A for older peripherals
- UHS-II SD and microSD, not token slots
- Full-size DisplayPort, no dongle required
- No drivers on macOS or Windows
- Separate audio in and out, front and rear
- 2.5 GbE for network storage
What to think about first
- Expensive — several times the price of a capable hub
- Dual displays depend on your computer, not the dock
- Needs its own mains adapter and desk space
- Most people will never use half the ports
- Thunderbolt host required for full bandwidth
- 2.5 GbE is wasted on a gigabit router
Hub or dock: how to decide
| If this describes you | Buy |
|---|---|
| Laptop, one monitor, a couple of peripherals, occasional charging | A USB-C hub |
| You travel and need ports in a bag | A hub or a compact travel dock |
| Fixed desk, one cable, two monitors, wired network, laptop charged under load | The TS4 |
| You offload camera cards weekly | The TS4 |
| Budget is the primary constraint | A USB-C hub |
What we could not assess
We have not measured sustained throughput across simultaneous ports, tested thermals under load, or run it through months of sleep-and-wake cycles — the failure mode that irritates dock owners most.
Every figure above is CalDigit’s published specification. What we can say is that the specification is unusually complete: CalDigit publishes a per-port power table and a bandwidth allocation diagram, which is more disclosure than most dock makers offer and makes it possible to check their claims against your own needs.
Frequently asked questions
Will the TS4 drive two external monitors?
On a Thunderbolt 4 Windows laptop, yes — one via the DisplayPort output and one via a downstream Thunderbolt port. On Apple Silicon it depends on your chip: base M-series MacBooks support only one external display over Thunderbolt, and no dock changes that without DisplayLink software.
Is 98 W enough to charge my laptop?
For most 13 to 16-inch laptops, yes, including under sustained load. Larger mobile workstations that ship with 140 W or higher adapters will charge more slowly, and may draw down slightly during heavy work.
Do I need Thunderbolt on my computer?
For full bandwidth, yes. It will work over USB-C, but you lose the 40 Gb/s link and the display options that depend on it. If your laptop has no Thunderbolt or USB4 port, a cheaper USB-C hub makes far more sense.
Does it need drivers?
No. It works natively on macOS and Windows without installing anything, which is one of the main reasons it gets recommended over docks that rely on DisplayLink.
Is a Thunderbolt dock worth it over a USB-C hub?
Only if you are hitting a limit. If your hub already handles your monitor, your peripherals and your charging, the dock adds cost and desk space rather than capability. Buy one when a hub has actually failed you, not in anticipation.
How fast are the card readers?
Both SD and microSD slots are UHS-II, an interface with a second pin row that carries substantially more bandwidth than the UHS-I readers on most docks. You need a UHS-II card to see the benefit.
- Anker 7-in-1 USB-C hub — the cheaper answer for most people
- Samsung T7 Shield — fast storage to hang off it
- LG UltraGear 27 OLED — a display for the DisplayPort output
- BenQ ScreenBar Halo 2 — lighting powered from a spare USB port
- Logitech MX Brio — needs USB 3.0, which the TS4 has plenty of
Sources. Port counts, per-port power delivery, bandwidth and card reader specifications are from CalDigit’s own documentation for the TS4. We have not tested this ourselves and do not claim to have.
Deciding between docks? See CalDigit TS4 vs OWC Thunderbolt Dock — three specifications settle it.