Anker 577 PowerExpand Review: 8.3/10 - Versatile Thunderbolt 4 Hub
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At a Glance
The Anker 577 PowerExpand earns an 8.3/10 out of 10 as a well-designed Thunderbolt 4 hub for users with modern Thunderbolt peripherals.
Prices last checked June 2026
Overview
The Anker PowerExpand 577 Thunderbolt 4 Hub (model A8398) is a compact docking solution that prioritizes Thunderbolt device connectivity over a wide variety of legacy ports. Priced at $249, it offers three Thunderbolt 4 downstream ports, an upstream Thunderbolt 4 port with 85 watts of laptop charging, and a 2.5 gigabit Ethernet port. Its slim, aluminum-clad design makes it ideal for users who need to connect multiple Thunderbolt peripherals and external drives. Unlike Thunderbolt 3 docks such as the CalDigit TS3 Plus, the Anker 577 uses Thunderbolt 4 protocol which guarantees minimum PCIe bandwidth, wake-from-sleep reliability, and DMA protection.
Design and Build
The Anker 577 is an elegant aluminum bar measuring 8.3 inches long, 2.2 inches wide, and just 0.6 inches tall, with a design that matches Apple’s aesthetic perfectly. Weighing approximately 490 g (17.3 oz), it has a solid feel that belies its compact size. The compact footprint takes up minimal desk space, and the included 36-inch Thunderbolt 4 cable offers flexibility in positioning. The top surface features a subtle Anker logo, and the aluminum enclosure serves as a passive heatsink to keep the dock cool under load.
Thunderbolt 4 Connectivity
The defining feature of the Anker 577 is its three Thunderbolt 4 downstream ports, each delivering 40 Gbps bandwidth for connecting external SSDs, eGPUs, or additional Thunderbolt displays. One downstream port supports up to 20W charging for connected devices, making it useful for powering a phone or tablet. The upstream port delivers 85W of laptop charging, which is sufficient for all but the most power-hungry 16-inch workstations. Thunderbolt 4 guarantees minimum PCIe 3.0 x4 bandwidth (32 Gbps), wake-from-sleep reliability, and Intel VT-d-based DMA protection against Thunderbolt attacks - features that set it apart from Thunderbolt 3 hubs.
Display Support
Through a single Thunderbolt 4 host connection, the Anker 577 supports up to two 4K displays at 60 Hz or a single 6K display at 60 Hz, leveraging DisplayPort Alt Mode over Thunderbolt. Unlike docks with dedicated HDMI or DisplayPort outputs, the display support is entirely dependent on the Thunderbolt downstream ports, which requires monitors with USB-C Thunderbolt input or the use of USB-C to HDMI or DisplayPort adapters.
Ethernet and USB-A
The built-in 2.5 gigabit Ethernet port is a genuine advantage over older Thunderbolt 3 docks still limited to 1 gigabit speeds. There are no USB-A ports on the hub itself, which is a notable omission for users who still rely on legacy peripherals. Anker includes a USB-C to USB-A adapter in the box, but the lack of native USB-A is a limitation compared to traditional docks.
Power Supply
The Anker 577 uses an external 120W power brick that delivers 85W to the laptop and the remaining 35W to power the hub and its connected peripherals. The power brick is compact for its wattage but adds to the cable clutter behind the desk. The hub supports power delivery negotiation, ensuring that connected devices receive the appropriate amount of power without overloading.
Pros
- Three Thunderbolt 4 downstream ports for modern peripherals and external SSDs
- 85W laptop charging through the upstream port
- 2.5 gigabit Ethernet for faster wired networking
- Compact, elegant aluminum design takes minimal desk space
- Thunderbolt 4 guarantees wake-from-sleep reliability and DMA protection
Cons
- No display output ports (HDMI or DisplayPort) requires adapters for monitors
- No native USB-A ports - USB-C to USB-A adapter is included but inconvenient
- Expensive at $249 for what is essentially a port expander, not a full dock
- External 120W power brick adds cable clutter behind the desk
Verdict
The Anker 577 PowerExpand earns an 8.3/10 out of 10 as a well-designed Thunderbolt 4 hub for users with modern Thunderbolt peripherals. The three downstream Thunderbolt 4 ports and 2.5 gigabit Ethernet are genuinely useful, and the build quality is excellent. The lack of any display output ports or USB-A ports limits its versatility compared to traditional docks, and the $249 price is steep for what is essentially a Thunderbolt expander rather than a full-function dock.
Sources
Where to Buy
Check current pricing on eBay or Amazon.
Prices last checked June 2026. Pricing and availability are accurate as of the date/time indicated and are subject to change.
📊 Comparison: Anker 577 PowerExpand vs. Competitors
| Specification | Anker 577 PowerExpand | CalDigit TS4 | CalDigit TS3 Plus | OWC Thunderbolt 4 Dock |
|---|---|---|---|---|
| Price | $249 | $379 | $249 | $199 |
| Ports | 3x TB4 downstream, 1x TB4 upstream, 2.5GbE | -- | 2x TB3, 2x DP 1.4, 5x USB-A 3.1, 1x USB-C 3.1, 10GbE, UHS-II SD, optical audio | 3x Thunderbolt 4 downstream, 1x upstream, 4x USB-A 3.2, 1x 2.5G Ethernet, SD 4.0 UHS-II, 3.5mm |
| Power Delivery | 85W upstream, 20W downstream | -- | 87W | 96W to host laptop |
| Bandwidth | 40 Gbps per port | -- | -- | -- |
| Ethernet | 2.5 Gigabit | -- | 10 Gigabit | -- |
| Dimensions | 8.3 x 2.2 x 0.6 in | -- | -- | 8.5 x 3.5 x 1.2 inches |
| Interface | -- | Thunderbolt 4 (40 Gbps) - host + daisy-chain | -- | -- |
| Downstream | -- | 3× Thunderbolt 4, 4× USB-A (10 Gbps), 2× USB-C (10 Gbps) | -- | -- |
| Display | -- | Dual 6K @ 60Hz or single 8K @ 60Hz | -- | -- |
| Networking | -- | 2.5 GbE Ethernet | -- | -- |
| Audio | -- | 3.5mm in/out, optical S/PDIF | -- | -- |
| Charging | -- | 98W Power Delivery to host laptop | -- | 180W external power supply |
| Storage | -- | UHS-II SD 4.0 card reader (312 MB/s) | -- | -- |
| Power | -- | 280W internal PSU (98W host + 110W peripheral bus) | -- | -- |
| Display Output | -- | -- | Dual 4K @ 60Hz or single 5K | -- |
| Build | -- | -- | Full aluminum chassis | -- |
| Standard | -- | -- | -- | Thunderbolt 4 / USB4 (40Gbps) |
| Daisy Chain | -- | -- | -- | Up to 5 Thunderbolt devices |
| Cable | -- | -- | -- | 0.8m Thunderbolt 4 cable included |
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