OWC Mercury Helios 5S Thunderbolt 5 (80Gb/s) PCIe Expansion Solution

OWC Mercury Helios 5S Thunderbolt 5 (80Gb/s) PCIe Expansion Solution delivers pro-grade PCIe expansion to thin notebooks, Mac Studio, small form factor PCs, and other machines that lack an internal PCIe slot. Connect with a single Thunderbolt or USB4 cable to run NVMe RAID storage, 8K capture cards, audio DSP, or high-speed networking at workstation-class speed — up to 6000MB/s of internal bandwidth — while adding three additional Thunderbolt 5 80Gb/s ports for next‑gen connectivity. Tool-free card installs, captive thumb screws, an aircraft-grade aluminum chassis, and a whisper-quiet adjustable fan make it simple to expand performance without bulky desktops or complicated setup. The Helios 5S is engineered for professionals who demand full-size PCIe card compatibility and a compact, dependable external solution.

Features and Benefits

• Up to 6000MB/s internal bandwidth for simultaneous read/write workloads.
• Single PCIe 4.0 x4 (x16 mechanical) slot supporting half-length, full-height, single- or double-width cards (including some with daughterboards).
• Three Thunderbolt 5 (USB-C) ports — 80Gb/s each — with 15W power delivery for devices and daisy‑chaining.
• Includes a certified 0.7m OWC Thunderbolt 5 (USB-C) 80Gb/s cable and power cord retainer; auto power on/off with host computer.
• Tool-free installation with captive thumb screws; removable mesh panel to accommodate double-width cards or daughterboards.
• Aircraft-grade aluminum housing with adjustable-speed fan for cool, near‑silent operation.
• Ideal for NVMe RAID, 8K video capture, high-speed Ethernet/fiber adapters, audio interfaces, and other pro PCIe cards.
• Notes card/power limits: cards requiring x8 lanes or more, or cards drawing more than 75W, are not supported; GPUs are not supported.

What's in the box

• OWC Mercury Helios 5S enclosure
• 0.7 m OWC Thunderbolt 5 (USB-C) 80Gb/s cable
• Power cord retainer
• Power cord
• 90W External Power Supply
• 1.8M (70.9") Power Cable
• Support Manual for OWC Mercury Helios 5S (digital)
• 3 Year OWC Limited Warranty

Product Q&A

• Q: Which cards can I install in the Mercury Helios 5S?
  A: The Helios 5S accepts half-length, full-height, single- or double-width PCIe cards (x16 mechanical slot) and supports PCIe 4.0 cards operating at x4 lanes. Removeable mesh and captive thumb screws make installs tool-free. Note that cards requiring x8 lanes or >75W are not supported and GPUs are explicitly not supported.
• Q: What connectivity and performance can I expect?
  A: The unit provides up to 6000MB/s internal bandwidth and three external Thunderbolt 5 (USB-C) ports, each rated at 80Gb/s and supplying 15W power delivery, enabling high-speed drives, displays, and daisy-chaining of Thunderbolt devices.
• Q: Will it work with my MacBook or Mac Studio?
  A: Yes — it is designed to expand Thunderbolt/USB4 Macs and small form factor Macs (MacBook family, Mac Studio, Mac mini) by providing external PCIe expansion via a single Thunderbolt/USB4 connection. Follow your PCIe card vendor’s driver instructions if a driver is required.
• Q: Is installation difficult or noisy?
  A: No — installation is tool-free with captive thumb screws and the unit is built with an aircraft-grade aluminum chassis and an adjustable-speed cooling fan for quiet, efficient operation.
• Q: What are important limitations to know before buying?
  A: Do not use GPUs with this enclosure. Do not install cards that require x8 PCIe lanes or draw more than 75W. If a card needs a vendor driver, install the driver per the card manufacturer’s instructions.

Specification

• Product: OWC Mercury Helios 5S
• Interface: Thunderbolt 5 / USB4 / Thunderbolt 4 / Thunderbolt 3 (Mac)
• External Ports: Three Thunderbolt 5 (USB-C) ports, 80Gb/s each, 15W power delivery each
• Included Cable: Certified 0.7 m OWC Thunderbolt 5 (USB-C) 80Gb/s cable
• PCIe Slot: One PCIe 4.0 x4 (x16 mechanical) — supports half-length, full-height, single- or double-width cards (including some with daughterboards)
• Internal Bandwidth: Up to 6000MB/s for simultaneous read/write
• Cooling & Chassis: Aircraft-grade aluminum housing with adjustable-speed cooling fan
• Installation: Tool-free with captive thumb screws; removable mesh panel for double-width cards
• Power: Internal power supply; power cord and retainer included; auto power on/off with host
• Limitations: Cards requiring x8 or more PCIe lanes or drawing >75W are not supported; GPUs are not supported.

Compatibility

Device Compatibility:

• Mac: Thunderbolt 5 and USB4 Macs; Thunderbolt 4 and Thunderbolt 3 Macs (Thunderbolt 3 compatibility specifically noted for Macs).
• PC: Thunderbolt 5, Thunderbolt 4, and USB4 PCs.
• Other Devices: USB4 devices supporting external PCIe/Thunderbolt host mode may connect, but functionality depends on host implementation.

Mac OS Compatibility:

• macOS 14.x Sonoma and newer

PC OS Compatibility:

• Windows 11

Other Requirements

• Thunderbolt 5 Mac systems require macOS 15.3.x or later.
• Intel based systems require macOS 15.x or later.
• Thunderbolt 3 support is Mac only and requires macOS 15.x or later.
• Linux systems require the latest version of Ubuntu.

Interface Requirements:

• Compatible host ports: Thunderbolt 5, Thunderbolt 4, USB4. Thunderbolt 3 support is explicitly mentioned for Macs.
• Requires a host that supports external PCIe/Thunderbolt device operation; some USB-C hosts without Thunderbolt/USB4 may not provide full functionality.

Incompatible / Unsupported:

• Not compatible with PCIe cards that require x8 lanes or draw more than 75W.
• Not compatible with GPUs (GPUs are not supported by this enclosure).