A docking station is a power strip for everything your laptop does at a desk: screens, charging, network and USB, all through one cable. That one cable is the main pipe. Its type and bandwidth decide how much can flow at once. The display specs say how many screens share the pipe and at what quality. Charging and USB ports take their share too. Check that your laptop's port matches the dock's pipe first, because the dock can never be faster than the laptop port it plugs into.
How the dock connects to your laptop: USB-C, USB4 or Thunderbolt, and whether the cable is fixed or replaceable.
When it matters: Trap: a Thunderbolt dock on a plain USB-C laptop falls back to basic mode with fewer screens and slower ports. A fixed cable cannot be swapped for a longer one.
The Thunderbolt generation: Thunderbolt 3 or 4 at 40 Gbps, or Thunderbolt 5 at 80 Gbps.
When it matters: Thunderbolt 5 docks run multiple high refresh 4K screens, but only on Thunderbolt 5 laptops. On older laptops they run at the older speed.
Skip it if: Skip it for USB-C docks.
The total data speed of the link between laptop and dock, in Gbps.
When it matters: Every screen and USB device shares this. At 10 Gbps, adding high resolution displays can cut USB speed sharply. 40 Gbps and up leaves room for both.
How the dock creates video: native through the laptop's graphics (Alt Mode or Thunderbolt), through MST, or through DisplayLink compressed video.
When it matters: DisplayLink adds screens on laptops that cannot drive many, but needs a driver, uses CPU, can lag in games and may block protected video in some apps.
How many external monitors the dock supports on a Windows laptop.
When it matters: The laptop's own graphics sets the true limit. A dock rated for three screens may only drive two on some laptops.
Skip it if you use one monitor.
How many external monitors the dock supports on Apple Silicon Macs, split by base chips and Pro or Max chips.
When it matters: Trap: base M-series Macs support fewer external screens than Pro and Max chips, and macOS does not support MST, so some docks only mirror on Mac.
Skip it if you do not use a Mac.
The highest resolution and refresh rate the dock can send to one monitor.
When it matters: A 4K 60 Hz dock wastes a 144 Hz monitor. Check the refresh at your monitor's resolution.
The resolution and refresh rate each monitor gets when two are connected.
When it matters: Many docks drop to lower refresh or resolution with a second screen. This is the number that matters for a dual monitor desk.
Skip it if you use one monitor.
Whether HDR (high dynamic range) video reaches your monitor through the dock.
When it matters: Needed for HDR movies and games on an HDR monitor. DisplayLink outputs often do not pass HDR.
Skip it if your monitor is not HDR.
The number and version of HDMI, DisplayPort and video-capable USB-C ports on the dock.
When it matters: Port versions set the ceiling: HDMI 2.0 tops out at 4K 60 Hz. Matching ports avoids adapters, which can limit refresh rate or HDR.
How much charging power the dock sends to your laptop, in watts, and the dock's own power supply.
When it matters: It should be close to your laptop's charger wattage, or the battery drains under heavy load. Bus-powered docks cannot charge the laptop at all.
How much power the dock's own ports give to phones and accessories, and whether they work when the laptop is unplugged.
When it matters: Useful for fast charging a phone or powering a portable drive. Offline charging lets the dock work as a desk charger.
Skip it if you only charge the laptop.
The number of USB-A and USB-C data ports, and their top speed.
When it matters: 10 Gbps ports suit fast external SSDs. Trap: "USB 3.2" can mean 5, 10 or 20 Gbps, so check the speed in Gbps.
Extra Thunderbolt ports on the dock for fast drives, more displays or another dock.
When it matters: Lets you chain devices at full Thunderbolt speed. All chained devices share the one link back to the laptop.
Skip it if you have no Thunderbolt devices.
Whether the dock uses separate USB controllers to spread load across ports.
When it matters: Reduces slowdowns when a fast drive and other devices are busy at once.
Skip it if: Skip it for light keyboard and mouse use.
The speed of the wired network port: 1 Gbps, 2.5 Gbps or faster.
When it matters: Wired network is steadier than Wi-Fi for calls and large downloads. 2.5 Gbps matters only with a fast network or NAS.
Built-in slots for camera memory cards.
When it matters: Handy for photographers. Check the reader speed class if you move large video files.
Skip it if you never use memory cards.
A slot inside the dock for an M.2 SSD that shows up as an external drive.
When it matters: Adds fast storage without another box on the desk. Speed depends on the dock's link and shares bandwidth with everything else.
Skip it if you have enough storage.
The headphone and microphone jacks on the dock.
When it matters: Lets you leave a headset plugged in at the desk. A combo jack needs a headset with a four-pole plug.
Skip it if you use USB or Bluetooth audio.
Lets two computers share the dock's screens and USB devices, switched with a button.
When it matters: Useful for a work laptop and a personal PC on one desk.
Skip it if you only connect one computer.
A slot for a cable lock that secures the dock to a desk.
When it matters: Matters in offices and shared spaces.
Skip it if: Skip it for home use.
Which operating systems the maker supports with this dock.
When it matters: Features like display count and DisplayLink drivers vary by system. Check your system is listed, not just the port type.