CalDigit TS4 Thunderbolt 4 Dock Review

Ports: 18 Is a Lot, and They Are the Right 18

The CalDigit TS4 provides 18 ports in total. On the rear are five Thunderbolt 4 downstream ports (40 Gbps each), five USB-A 10Gbps ports, one DisplayPort 1.4 output, one USB-C 10Gbps port, Gigabit Ethernet, a UHS-II SD reader, and a microSD reader. The front panel adds two USB-C ports (one 10Gbps, one 20Gbps), one USB-A port, a 3.5 mm audio combo jack, and a digital audio out.

Five Thunderbolt 4 downstream ports is more than most desktop setups need, but the headroom means external NVMe enclosures, high-resolution displays, and downstream Thunderbolt devices can all connect without daisy-chaining. Bandwidth is shared across the chain, which is adequate for typical multi-drive workflows.

The UHS-II SD reader is the clearest differentiator at this price. Many docks ship only UHS-I readers, which are capped at roughly 104 MB/s; a UHS-II reader targets the faster bus used by pro-grade cards, which matters for photographers and videographers who offload raw or ProRes footage.

The front-facing audio combo jack is a small but practical detail: a headset can stay plugged into the dock rather than the laptop, so docking and undocking involves one cable instead of two.

Charging: 98W Handles the 16-inch MacBook Pro

The TS4 delivers 98W of host charging over its Thunderbolt 4 connection. According to CalDigit specifications, that is enough to charge a 16-inch MacBook Pro under sustained load, which draws between 96W and 100W during demanding tasks such as video encoding. Docks that cap at 60W or 85W can leave a 16-inch MacBook Pro draining under heavy load even while plugged in.

A 14-inch MacBook Pro draws less under load, so the 98W ceiling is more headroom than that machine requires. Buyers who may later move to a 16-inch model still benefit from the higher limit.

One documented caveat: the USB-A ports are rated at 7.5W, which is fine for peripherals but slow for an iPhone, and the front USB-C ports are rated at 20W. A dedicated USB-C charger is faster for phones.

Display Support: Dual 4K@60Hz Without Compromise

The TS4 drives dual 4K monitors at 60Hz simultaneously using the full 40 Gbps bandwidth of Thunderbolt 4, without the refresh-rate caveats that affect USB-C docks relying on DisplayPort Alt Mode. Standard USB-C docks typically split bandwidth and cap the second display at 4K 30Hz or lower.

For single-display setups, the dock supports one 8K display at 30Hz or one 6K display at 60Hz over a downstream Thunderbolt port, which is useful for 6K and 8K workflows.

Important caveat: base M1 MacBooks support only one external display regardless of the dock, a hardware limitation of the chip rather than the dock. M1 Pro, M1 Max, M2 Pro, M2 Max, M3, and M3 Pro chips support dual displays. Buyers should confirm the chip in their Mac before purchasing.

Data Transfer: Full Thunderbolt Speed

Each of the five downstream Thunderbolt 4 ports provides the full 40 Gbps of Thunderbolt bandwidth, shared across the chain. With a single NVMe enclosure attached, a Thunderbolt 4 dock can approach the direct-to-Mac speed of the enclosure; adding a second high-bandwidth device to the chain splits the available bandwidth between them.

The USB-A ports are rated at 10 Gbps each, which is sufficient for external hard drives, audio interfaces, and most peripherals, while the rear USB-C 10Gbps port targets fast external SSDs.

For most workflows the dock bandwidth is not the limiting factor — the TS4 has more headroom than the peripherals typically attached to it.

Build Quality and Thermals

The TS4 is an aluminum chassis weighing 1.6 lbs and measuring roughly 9 x 9 x 2 inches. The metal body acts as a heatsink, so the dock warms under sustained load without becoming hot, and it is fanless — a deliberate design choice that keeps it silent in a quiet room, in contrast to some competing docks that use a small audible fan.

The power supply is a separate 180W brick, which is large and runs warm; buyers typically place it under a desk or behind a monitor. The included 0.5 m Thunderbolt 4 cable is short, so a longer active Thunderbolt cable may be required if the laptop sits on a stand.

Daisy-Chaining

The TS4 supports Thunderbolt daisy-chaining, so a second Thunderbolt device — an external NVMe enclosure, a second dock, or a Thunderbolt display — can be connected downstream from the TS4, up to six devices deep in theory. Bandwidth is shared across the chain.

Daisy-chaining is useful when the 18 ports of the TS4 are fully occupied and a further dock is needed without consuming another Thunderbolt port on the host Mac.

Firmware Stability

Firmware stability is where premium Thunderbolt docks separate themselves from budget alternatives. The TS4 is designed to maintain display, Ethernet, and peripheral connections across sleep and wake cycles without reconnect loops or dropouts, and CalDigit distributes firmware updates through its firmware tool.

By comparison, some competing Thunderbolt docks have required a firmware update out of the box to resolve display flicker or periodic monitor dropouts — classes of issue the TS4 is not associated with.