How to add PCIe cards to just about any Mac

With Apple launching the brand new Mac Pro with not only the M2 Ultra processor under the hood, but also PCIe expansion built right in, there's refreshed attention being put on PCIe cards.

The Mac Pro is a powerhouse of a machine, featuring PCIe slots that utilize the new PCIe Gen 4 standard, offering up even faster connectivity and the ability to connect to higher-performance devices. For example, PCIe Gen 4 cards with multiple SSDs can theoretically reach speeds up to 26 gigabytes per second.

However, the Mac Pro is wildly expensive, which means for the folks who are looking to expand their computer's functionality while staying within a specific budget, other PCIe expansion chassis options might be worth considering.

And thanks to Thunderbolt, adding a variety of different PCIe cards is as easy as nailing down which enclosure you want to put them in.

What is a PCIe expansion chassis?

A PCIe expansion chassis, is a quick and easy way to store a single or multiple PCIe cards in a single unit. This enclosure allows for a Mac to connect to these cards via Thunderbolt, and it works the same with a MacBook as well thanks to the easy connectivity.

That enclosure features not only the mounting elements for each PCIe card, but also usually a power supply. It's also possible that the expansion chassis features other stock elements right out of the box, including additional USB connections or Ethernet ports.

Any x16 PCIe card that is fully supported in macOS can be installed in a PCIe expansion chassis. Speeds are limited to about 32 gigabits per second — or about x4 speeds for PCIe 3.0.

eGPU enclosures come with an asterisk

Technically speaking, an eGPU enclosure can serve as an PCIe expansion chassis, as most of them feature slots for at least one PCIe card. However, these enclosures are primarily meant for adding more graphical performance to a laptop or desktop.

Thing is, Apple doesn't support external GPUs — or any GPU besides what's on-die — on its M-series computers, both the M1 and M2. Which means if you go with an eGPU enclosure, keep that in mind, even if your primary use is still as an PCIe expansion chassis.

If you still use an Intel-based Mac, however, that will work with an eGPU enclosure. So far, they work fine in the macOS Sonoma beta on Intel machines.

Check for support and other stipulations

While Thunderbolt makes it easy to connect to a PCIe expansion chassis, that doesn't necessarily mean the PCIe card that you own that you put inside that enclosure will work with your Mac. You need to make sure you check for compatibility with Mac first, and then, if you are using an Apple Silicon device, make sure that the card supports these processors as well.

Another thing to be aware of when using a PCIe expansion chassis is daisy chaining. Not all enclosures support this, but if it does you'll need to make sure that you set up your devices on the daisy chain in appropriate locations.

With each device connected via Thunderbolt, connection speeds will be impacted, which means performance could weaken further along the chain you go. Make sure you have your equipment set up in an appropriate way so as not to degrade performance while you're trying to get things done.

Depending on your needs, a PCIe expansion chassis can help you with your daily routine in a variety of different ways. Even if it's just a need for more ports, video capture, or more storage, these expansion chassis options can help out.

Here are the top picks for PCIe expansion chassis.

Sonnet DuoModo

The DuoModo PCIe expansion chassis from Sonnet is designed to stay compact, while keeping its performance and usability high enough for the enterprise market more than the personal one. This enclosure can be used as an eGPU or PCIe expansion chassis, and it can also also house a Mac mini for good measure.

There are actually three enclosures in the DuoModo, with options for two-module rack-mount or single-module and dual-module versions. The xMac mini module boasts an additional Thunderbolt 3 port, while also offering access to a single USB 3.2 Type-A port, a pair of USB-C ports, and two M.2 NVMe SSD sockets that can add storage as needed.

The eGPU module can hold one PCIe card, which will connect via the Thunderbolt 3 cable to the Mac. This is obviously geared towards heavy graphics usage thanks to its 800W power supply, it will cover the PCIe expansion bases as needed as well.

As is par for the course with Sonnet and enclosures, there are several configurations users can choose from. If you want a single-module enclosure the price starts at $99.99, or you can opt to pay $149.99 for the dual-module enclosure.

If you want more PCIe card options, the DuoModo Echo III Module, which is the same as the Echo III enclosure listed below, sports three PCIe slots, which can all be full-height, full-length. It also supports AVID-qualified audio tools, including HDX PCIe cards. It has a 400W power supply and it retails starting at $999.99.

StarTech Thunderbolt 3 PCIe Expansion Chassis with Display Port

StarTech's PCIe expansion chassis focuses primarily on building out a workstation, based on your specific needs. It works with either a desktop or laptop computer thanks to supporting Thunderbolt 3, with up to 40Gbps bandwidth support.

The hardware supports DisplayPort video output, so you can quickly connect a separate external monitor as needed. And the PCIe expansion chassis supports daisy chaining a total of six different Thunderbolt 3 devices.

The chassis also supports adding several different PCI Express cards, including eSATA, SSD, video capture, FireWire, and PCIe USB 3.1/3.0/2.0, and USB-C options.

StarTech's PCIe expansion chassis works with Macs or Windows PCs. It's available from several different resellers, including Amazon for $305.76.

OWC Mercury Helios 3S PCIe expansion chassis

OWC's PCIe expansion chassis offers up a pair of Thunderbolt 3 ports, each offering 40Gb/s transfer speeds. But one of the primary reasons to use this enclosure is its small stature, while still offering plenty of expansion opportunities.

If you need an external monitor, the Mercury Helios 3S supports that with a DisplayPort 1.4 connection that can handle an 8K monitor. It even offers up 85W laptop charging.

OWC's option supports PCIe (x16) with support for half-length, full-height, single- or double-width cards. And if you need even more hardware support, the Mercury Helios 3S supports daisy chaining up to five additional Thunderbolt devices.

The enclosure is fully supported by Mac and Windows, and OWC says there are no drivers necessary or tools to install cards. OWC's Mercury Helios 3S supports video capture cards, digital audio needs, SSD, eSATA, FireWire, USB host adapters, and much more.

OWC's Mercury Helios 3S with its single external PCIe slot is available from the company's website for $264.99.

Sonnet Echo III Desktop PCIe expansion chassis

Sonnet's Echo III Desktop PCIe expansion chassis can handle three cards, making it one of the more versatile options right out of the box. It supports both Thunderbolt 4 and Thunderbolt 3, and supports Mac, Windows, and Linux.

The Echo III Desktop supports SAS/SATA, SSD, networking, audio, and video PCIe cards, as long as they support Thunderbolt.

This particular expansion chassis is particularly capable for audio professionals. It's been tested and qualified by the Avid Audio group and supports Avid Pro Tools HD 2020 software, along with Pro Tools HDX PCIe cards without requiring any extra tools to install them.

As far as the slots are concerned, the Sonnet Echo III Desktop supports one x16 and two x8 slots. This means the expansion chassis can handle full-height, single-width cards or a single double-width card and one single-width card.

The Sonnet Echo III Desktop is available now from the company's website for $1,099.99.

OWC ThunderBay Flex 8 PCIe expansion chassis

If you aren't concerned with desk space, and you don't use a Windows PC, then OWC's ThunderBay Flex 8 might be the way to go. Especially if you have a very large workflow on a day-to-day basis.

This Mac-only piece of hardware supports eight drive bays, with a combination of U.2/M.2 Non-Volatile Memory Express (NVMe) and SAT/SASA drives that can equal up to 172TB of storage space. All of that also equals up to 2,750MB/s real world speeds.

The ThunderBay Flex 8 supports DisplayPort 1.4 for the ability to connect an external 8K monitor. It offers a pair of Thunderbolt 3 ports, one at 15W and the other at 85W.

It offers a single PCIe expansion slot, which supports a single full-height, half-length, single-width card that can handle video capture or other tasks.

OWC's ThunderBay Flex 8 supports daisy chaining up to 5 different Thunderbolt 3 devices.

The expansion chassis is available from OWC's website in various configurations starting at $1,399.99.

eGPU enclosures

We're including some eGPU enclosures in this list for good measure, but it's worth noting again that Apple does not support external GPU options for its Apple Silicon computers.

With that being said, if you already own an Intel-based eGPU option you'll be able to keep using it as a PCIe expansion chassis, so something to keep in mind.

Here are the top picks for eGPU enclosures.

Razer Core X Chroma

The Razer Core X Chroma is first and foremost an eGPU enclosure, which means it's not compatible with any of Apple's M-series computers for that specific need. However, it also serves as a capable PCIe expansion enclosure, too.

It supports 3-slot-wide full-size cards, and supports Windows machines as well. As for the GPU side of things, the Razer Core X Chroma supports both AMD XConnect-enabled Radeon cards and NVIDIA's GeForce cards.

The Core X Chroma supports Thunderbolt 3 and Thunderbolt 4, and a 3-Slot wide, full-length, PCI-Express x16 graphics card. There is just the single Thunderbolt 3 port, but the enclosure also offers four USB 3.1 Type-A ports and a Gigabit Ethernet port.

It can handle 100W power delivery, which is more than enough to keep a MacBook Air or MacBook Pro powered up.

The Razer Core X Chroma is available from Razer's website for $499.99.

AKITIO Node Pro

The AKITIO Node Pro is another Thunderbolt 3 enclosure. As was the case with the Razer option, this eGPU option is not meant for M-series Mac hardware. It only supports Intel-based Mac computers running macOS 10.13.4 or later.

This enclosure supports a single PCIe x16 slot, which offers room for full-height, full-length, or double-width desktop cards. There is a single Thunderbolt 3 port that supports speeds up to 40Gbps.

There is a 650W internal power source, along with a pair of 8-pin PCIe connectors. It also supports a single DisplayPort 1.4 connection that can run a pair of 4K external monitors.

AKITIO's Node Pro can daisy chain up to six additional Thunderbolt 3 devices.

The Node Pro is available now for $279.00 from B&H.