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OWC Mercury Helios 3S

OWC Mercury Helios 3S OWC Mercury Helios 3S Front OWC Mercury Helios 3S Back

OWC Mercury Helios 3S


1External PCIe Slot

Add half-length, full-height, single or double-width cards

Quick Specs:

  • Thunderbolt 3
  • Mac & Windows

Use PCIe cards with your Thunderbolt (USB-C) Mac or Windows PC

  • Lightning-fast 40Gb/s transfer speeds: (2) Thunderbolt (USB-C) ports
  • See more: DisplayPort 1.4 for connecting up to an 8K display
  • Charge while working: 85W of notebook charging
  • Secure workflow: locking 12V power connector
  • Maximum potential: daisy-chain up to 5 additional Thunderbolt devices
  • Easy card installs: no tools required

  • Performance & reliability at an exceptional value

  • Wide array of models & options

  • OWC expansion solutions consistently receive top ratings

  • Industry-leading warranty & support. Get help »


OWC Mercury Helios 3S

Add an external PCIe slot to your Thunderbolt (USB-C) equipped computer.

OWC Mercury Helios 3S Bundles

Add 10GbE network connectivity with the flexibility of future PCIe expansion.

OWC Mercury Helios 3S

Maximize Your PCIe Card Investment

Using a video, audio, storage, network, or even gaming PCIe card with a Mac Pro or PC desktop is a simple matter of inserting your card into an open slot. But what do you do if you have a laptop or even a space-confined desktop like an iMac or Mac mini that doesn't contain a PCIe slot?

The Mercury Helios 3S is an easy to use yet powerful expansion solution that adds an external PCIe slot to your Thunderbolt (USB-C) equipped computer. Now you can maximize your existing PCIe card investment — or expand it! — while enjoying the flexibility of adding professional-class video production, transcoding, audio processing, data storage, and high-speed network connectivity to your machine.

OWC Mercury Helios 3S with PCIe Expansion Cards

Retask Without Limits

Instead of buying one or more function-dedicated Thunderbolt interface devices, you can use Mercury Helios 3S like a dock for multiple PCIe cards. Capture incredibly high-quality audio with a PCIe audio card and then retask Helios 3S with a PCIe SSD card to edit and archive tracks. You can swap cards in minutes, adding a new level of flexibility to your workflow.

OWC Mercury Helios 3S in Video Studio

Capture, Stream, and Share in Seconds

With dual 40Gbps Thunderbolt (USB-C) ports, the Mercury Helios 3S offers the bandwidth needed to support data-intensive 4K capture cards to speed up diverse video workflows such as vlogging. Boost your DAW with external DSP acceleration and run larger mixes with multiple plug-ins. Livestream the action in your gaming sessions or share files over a 10GbE or Fibre Channel network without any speed throttling.

OWC Mercury Helios 3S with OWC Mercury Electra 6G SSD

Pro-Level Performance Cards for Every Need

Mercury Helios 3S supports a wide variety of half-length, full-height, single or double-width pro-level PCIe cards from leading brands like AJA, Apogee, ATTO, Avid Pro Tools, Blackmagic Design, CalDigit, HighPoint, Intel, Solid State Logic, Universal Audio, and OWC:

  • Video capture
  • Digital audio
  • Solid State Drive (SSD)
  • 40GbE/10GbE network adapters
  • SAS controllers
  • Firewire, USB, or eSATA host adapters

Add New Capabilities to Your Workflow

Mercury Helios 3S leverages the full power of Thunderbolt to deliver added potential to your Mac or PC. Daisy-chain up to five additional Thunderbolt peripherals for incredible capabilities to work or play. Learn the basics of daisy-chaining Thunderbolt devices for maximum performance in this handy infographic. View Infographic.

Thunderbolt Device Daisy Chain Infographic
OWC Mercury Helios 3S with Drive

Quick and Easy Card Swaps with Mercury Helios 3S

  1. Disconnect Mercury Helios 3S Thunderbolt cable from computer
  2. Disconnect power cord from Mercury Helios 3S
  3. Remove two thumb screws and swap card
  4. Reconnect power cord to Mercury Helios 3S
  5. Reconnect Mercury Helios 3S Thunderbolt cable to computer

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

Thunderbolt Logo

Thunderbolt Made Easy

We make it easy to choose the right gear. Our Thunderbolt Certified products offer the same performance and functionality whether they are Thunderbolt 3 or Thunderbolt 4. And if you’re rocking a beloved Thunderbolt 2 machine, we offer an adapter so you can plug into our universe of award-winning solutions. No hassles, no confusion. That’s the OWC Difference.

Apple Mac models with Thunderbolt 2/Thunderbolt ports can be connected using an Apple Thunderbolt 3 (USB-C) to Thunderbolt 2 Adapter and a Thunderbolt 2 cable (available separately). This configuration provides data transfer at up to 20Gb/s but does not support notebook charging.

OWC Thunderbolt (USB-C) Cable

OWC Thunderbolt Cable Included

OWC Mercury Helios 3S comes with a certified OWC Thunderbolt (USB-C) Cable. But if your workflow demands a different length to make the connection, OWC Thunderbolt (USB-C) Cables are the perfect choice.

OWC ClingOn

Stabilize Thunderbolt and USB-C Cables

Unexpected disconnects during file transfers or a work session can be devastating. OWC ClingOn custom cable stabilizers (sold separately) are the quick and easy way to reduce – if not completely eliminate – cable strain on Thunderbolt and USB-C connections so you can work with confidence even in the highest traffic environments.

OWC, Trusted by Pros & Enthusiasts the World Over

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 our hardware with a 3 Year OWC Limited Warranty and award-winning customer support.

Learn More

Get More from OWC Mercury Helios 3S

OWC U.2 NVMe Interchange System for Mercury Helios 3S

OWC U.2 NVMe Interchange System for Mercury Helios 3S

Add swappable U.2 NVMe drive capability with 2631MB/s real-world speeds!

By combining a locking drive bay and removable tray, the OWC U.2 NVMe Interchange System turns the Mercury Helios 3S into a time and money-saving swappable U.2 NVMe SSD storage solution for high-performance film/video production requirements.

Shop OWC U.2 NVMe Interchange System for Mercury Helios 3S »