OWC Mercury Helios 5S Thunderbolt 5 PCIe expansion enclosure

OWC Mercury Helios 5S

The powerfully simple way to use PCIe cards with Thunderbolt 5/4/3 and USB4 machines like the Mac Studio — plus three extra Thunderbolt 5 ports.

AddsPCIe Slotto space-constrained Macs & PCs

Up To6000MB/scards + external storage at once

InstallTool-Freecaptive thumb screws

Adds3× TB5USB-C ports, 15W each

Thunderbolt 5 (80Gb/s)PCIe 4.0 x4 (x16 slot)3× TB5 (USB-C) portsTB5/4/3 + USB4Aluminium + quiet fanMac & PC

OWC

Mercury Helios 5S

External Thunderbolt 5 PCIe expansion for Macs and PCs, with three extra TB5 ports.

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Expand Your Capabilities Effortlessly

Give your notebook, small form factor, or all-in-one desktop pro-grade, full-size workstation capabilities. Use ultra-fast storage, 8K video capture, audio DSP, or high-speed networking PCIe cards over a single Thunderbolt or USB4 connection — with no tools required.

Plus, three additional Thunderbolt 5 ports give you a handy next-gen connectivity hub. Mercury Helios 5S lets you think outside the traditional bulky desktop box when it comes to PCIe-based workflows.

Two OWC Mercury Helios 5S units, front and rear

Everything You Need to Add a PCIe Slot

Internal Class SpeedUp to 6000MB/s bandwidth for simultaneous read/write.

Widely CompatibleWorks with Thunderbolt 5/4, USB4 Macs and PCs, and Thunderbolt 3 Macs.

Expands Small MachinesUse video capture, high-speed fiber/Ethernet, NVMe RAID, audio I/O, and other cards to unlock MacBooks, Mac Studio, Mac mini, and machines lacking a PCIe slot.

Whisper QuietAircraft-grade aluminium housing with a high-efficiency cooling fan for cool, nearly silent operation.

Pro-Level Card Ready(1) PCIe 4.0 x4 (x16 mechanical slot) for half-length, full-height, single or double-width cards.

Easy Card InstallsCaptive thumb screws — no tools required.

Expanded ConnectivityThree Thunderbolt 5 (USB-C) 80Gb/s ports, each with 15W power delivery.

Complete and SecureIncludes a Thunderbolt 5 80Gb/s cable and power cord retainer.

OWC Mercury Helios 5S with a range of pro PCIe cards

Full-Speed PCIe Performance Ahead

Forget the belief that internal is always faster than external. Mercury Helios 5S delivers up to 6000MB/s of bandwidth, so you can run modern PCIe 4.0 cards at full speed while still accommodating data-hungry external Thunderbolt drives.

Whether you’re editing multi-cam 8K footage, running real-time audio processing, or moving terabytes across a 25GbE network card, you get the performance you’d expect from an internal PCIe slot with the flexibility of an external one.

Installing a PCIe card inside the OWC Mercury Helios 5S

Install Cards in Seconds

A tool-free design compatible with half-length, full-height, single or double-width pro-level cards from leading brands like AJA, Apogee, ATTO, Avid Pro Tools, Blackmagic Design, RME, Universal Audio, and OWC.

Disconnect the Thunderbolt cable and power cord from Mercury Helios 5S.
Loosen the two captive thumb screws and install your PCIe card.
Reconnect the Thunderbolt cable and power cord.

If your PCIe card requires a driver, always follow the manufacturer’s instructions for installation.

Triple Your Possibilities

Beyond PCIe expansion, Mercury Helios 5S is a space- and money-saving way to add both capability and convenience to your workspace. With three Thunderbolt 5 (USB-C) ports — each capable of 80Gb/s throughput and 15W of power delivery — you can easily connect high-performance drives, 8K displays, or other peripherals.

Producer using OWC Mercury Helios 5S in a studio workflow

Ready for Today and Yesterday

Whether you’re pushing a Thunderbolt 5 machine to its max or still relying on a trusty Thunderbolt 3/4 Mac, Mercury Helios 5S offers plug-and-play expansion across Thunderbolt and USB4 generations. Your PCIe card is secured in an aircraft-grade aluminium chassis with a nearly silent, high-efficiency fan — so you and the Helios 5S stay cool under pressure.

Highlights

Expands small machines that lack a PCIe slot
Internal-class speed: over 6000MB/s (simultaneous read/write)
(1) PCIe 4.0 x4 (x16 mechanical slot) — half/full-height, single/double-width
Three Thunderbolt 5 (USB-C) 80Gb/s ports, 15W PD each
Aircraft-grade aluminium with a whisper-quiet fan
Works with Thunderbolt 5/4/3 and USB4
Tool-free install with captive thumb screws
Certified OWC Thunderbolt 5 cable included

What’s in the Box

(1) OWC Mercury Helios 5S PCIe Expansion Solution
(1) 0.7M (28″) Thunderbolt 5 Cable
(1) 90W External Power Supply
(1) 1.8M (70.9″) Power Cable
(1) Getting Started QR Insert Card
3 Year OWC Limited Warranty

OWC Thunderbolt Cable Included

OWC Mercury Helios 5S comes with a certified 0.7-meter OWC Thunderbolt 5 (USB-C) cable. If your workflow demands a different length, OWC Thunderbolt 5 (USB-C) cables are the perfect choice.

OWC, Trusted by Pros & Enthusiasts the World Over

We build our hardware to the highest standards of reliability and performance. Because 100% reliability is always the goal, we rigorously quality-test and back the Mercury Helios 5S with a 3 Year OWC Limited Warranty and renowned support.

Up to 6000MB/s bandwidth available for simultaneous read/write; actual throughput depends on the installed card, host, and connected devices.
PCIe slot: (1) PCIe 4.0 x4 in an x16 mechanical slot for half-length, full-height, single or double-width cards.
Each Thunderbolt 5 (USB-C) port provides up to 80Gb/s and 15W power delivery; display and device support depend on host computer capabilities.