The ASMedia ASM4242 is a USB4 host controller chip that has achieved Thunderbolt 4 certification, making it a key component for PCIe expansion cards. By installing a card based on this chip, you can add USB4/Thunderbolt 4 ports to your desktop PC, enabling up to 40 Gbps data transfers.

Key Features

  • Thunderbolt 4 certified, passing Intel's rigorous compatibility tests
  • Supports USB4 standard with up to 40 Gbps bandwidth
  • PCIe Gen4 x4 interface for host connection
  • Daisy-chain support for up to six Thunderbolt devices
  • Up to 100W USB Power Delivery (depending on implementation)

Compatibility Guide

This controller uses PCIe Gen4 x4 lanes, so a compatible motherboard PCIe slot is required. Being Thunderbolt 4 certified, it offers high compatibility with Intel-based systems and backward compatibility with Thunderbolt 3 and USB4 devices. On AMD platforms, it works as USB4, but full Thunderbolt 4 functionality is best achieved on Intel platforms.

Ideal Use Cases

  • Adding Thunderbolt 4 ports to an existing desktop PC
  • Creators who need fast external storage or docks
  • Professionals connecting multiple Thunderbolt devices via daisy chain

Upgrade Considerations

When installing an expansion card with this controller, ensure your motherboard has a PCIe Gen4 x4 or higher slot. To fully utilize Thunderbolt 4, you'll need compatible cables and devices. Using a PCIe Gen3 slot will halve the bandwidth, so aim for Gen4 for maximum performance.