Dell’s Thunderbolt docks can get confusing fast.
WD22TB4, WD25TB4, SD25TB4 — the names are close, the designs look similar, and on paper they all look powerful. But in real life, they’re built for different generations of users.
If you’re trying to answer one simple question —
“Which one should I actually buy?” — this guide is for you.
Quick answer (for impatient readers)
- WD22TB4: older, still usable
- WD25TB4: the best choice for most people today
- SD25TB4: same hardware as WD25TB4, but designed for IT teams
If you’re buying new in 2025, start with WD25TB4 and only look elsewhere if you have a specific reason.
How these docks are related
Think of them as a timeline:
WD22TB4 → WD25TB4 → SD25TB4
- WD22TB4 is the previous-generation workhorse
- WD25TB4 is the current-generation upgrade
- SD25TB4 is essentially WD25TB4 with enterprise-grade management features
From a performance standpoint, WD25TB4 and SD25TB4 behave almost identically for end users.
What they all do well
Let’s start with what doesn’t affect your decision.
All three docks offer:
- True Thunderbolt 4 (not USB-C pretending to be a dock)
- Up to 130W charging for Dell commercial laptops
- Strong compatibility with Windows, Linux, and macOS
- Apple certification for MacBooks
- Solid build quality and long-term stability
If you want to understand the technical differences between Thunderbolt 3, 4, and USB-C in more depth, see our complete Thunderbolt vs USB-C guide.
If your setup is basic — keyboard, mouse, Ethernet, and one or two monitors — any of these docks will work just fine.
The differences show up once your setup gets more demanding.
Display support: where the generations really separate
WD22TB4: still usable, but clearly from an earlier generation
WD22TB4 was designed around earlier DisplayPort bandwidth limits. It works well for common office setups, but it becomes more restrictive as you add higher resolutions or more displays.
Typical display configurations with WD22TB4
| Monitor setup | Supported |
|---|---|
| 1 × 4K @ 60Hz | Yes |
| 2 × 4K @ 60Hz | Yes |
| 3 × QHD (2560×1440) @ 60Hz | Yes |
| 4 × QHD @ 60Hz | Yes (HBR3 systems) |
| 3 × FHD (1920×1080) @ 60Hz | Yes |
| 4 × FHD @ 60Hz | Yes (HBR3 systems) |
| 1 × 5K @ 60Hz | Yes (Thunderbolt systems) |
| 1 × 8K @ 60Hz | Limited (requires HBR3 + DSC support) |
What this means in real life:
- Two 4K monitors at 60Hz is the realistic sweet spot
- Three or four displays usually require dropping to QHD or FHD
- 5K and 8K are possible, but only with specific system support
- There’s less flexibility compared to newer-generation docks
If your setup is mostly standard 1440p or 4K monitors, WD22TB4 still does the job. If you’re planning a display upgrade, this is where it starts to feel dated.
WD25TB4 and SD25TB4: built for modern displays
WD25TB4 and SD25TB4 share the same display architecture. From a display standpoint, they behave the same in daily use.
They support DisplayPort 1.4 and 2.1, along with full Display Stream Compression (DSC).
Typical display configurations with WD25TB4 / SD25TB4
| Monitor setup | Supported |
|---|---|
| 2 × 4K @ 60Hz | Yes |
| 4 × 4K @ 60Hz (with DSC) | Yes |
| 3 × 4K @ 60Hz | Yes |
| 1 × 5K ultrawide (5120×2160) @ 60Hz | Yes |
| 2 × 6K @ 60Hz | Yes |
| 1 × 8K @ 60Hz | Yes |
Important reality check:
The dock can support these configurations, but your laptop GPU and operating system still set the final limit, especially on macOS.
Ports: small changes that matter day to day
HDMI 2.1 is a quiet but meaningful upgrade
| WD22TB4 | WD25TB4 / SD25TB4 | |
|---|---|---|
| HDMI | 2.0 | 2.1 |
HDMI 2.1 improves compatibility with newer monitors and TVs and reduces display handshake issues when mixing HDMI and DisplayPort outputs.
USB and Ethernet finally catch up
| WD22TB4 | WD25TB4 / SD25TB4 | |
|---|---|---|
| USB-A speed | 5Gbps | 10Gbps |
| USB-C data | Mixed | 10Gbps across all ports |
| Ethernet | 1GbE | 2.5GbE |
If you use fast external SSDs or work on a 2.5Gb network, WD25TB4 and SD25TB4 feel noticeably faster in daily use.
So why does SD25TB4 exist?
Here’s the short version:
SD25TB4 is not designed for individual buyers.
It adds features most people will never use:
- Remote firmware updates without a connected PC
- Zero-touch deployment
- Cloud-based dock fleet management
For IT teams managing large numbers of docks, these features matter. For home or small-office users, they don’t.
Which one should you buy?
Choose WD22TB4 if:
- You already own one and it works
- Your monitor setup is simple
- You want a lower-cost, proven dock
Choose WD25TB4 if:
- You’re buying new
- You use 4K or ultrawide monitors
- You want faster USB and Ethernet
- You want a dock that will stay relevant longer
👉 This is the model we recommend to most DockSelector readers.
Choose SD25TB4 if:
- You manage docks at scale
- You need remote management and deployment
- You already know why you need it
Final takeaway
- WD22TB4: reliable, but aging
- WD25TB4: modern, flexible, and future-proof
- SD25TB4: WD25TB4 plus enterprise control
If you’re unsure whether SD25TB4 is worth it, the answer is usually no. For almost everyone else, WD25TB4 is the right balance.
Looking for USB-C alternatives? If you don't need Thunderbolt 4's advanced features, see our WD25 vs WD25Z vs SD25 comparison for USB-C Pro dock options.
Wonder which dock is compatible with your laptop? Use our dock-laptop compatibility checker.