Thunderbolt 4 Rackmount and Tower Industrial Computers from DuroPC — With Full PCI/PCIe Expansion

Rackmount computers with a Thunderbolt interface are hard to find. DuroPC offers several, in 2U, 3U, 4U and tower configurations, each keeping the PCI and PCIe expansion slots that industrial and test-and-measurement systems depend on.

Engineers who buy a rack-mounted industrial computer usually need two things at once: the expansion slots to host their data acquisition, motion control, frame grabber, or avionics bus cards, and the fast external connectivity that modern test equipment now expects. Thunderbolt is the connection many newer instruments use, but it is almost never offered on rack-mount industrial computers. DuroPC does.

This article expands on our earlier overview, Enhancing Industrial Computing: Unveiling the Power of Thunderbolt 4, with the specific systems, the engineering behind them, and the instruments they connect to.

DuroPC Computers with Thunderbolt 4

DuroPC offers Thunderbolt 4 on three processor and slot configurations. Each configuration is available in several chassis sizes, so you can match the computer to the rack space you have.

15th Gen Intel Core Ultra — Thunderbolt 4 ports built in

Expansion: 2x PCIex16 (5.0), 3x PCIex4, 2x PCIex1

• 4U Rackmount — RX1715-4
• 3U Rackmount — RX1715-3
• 3U Front I/O Rackmount — RX1715-3-FIO
• 2U Low Profile Rackmount — RX1715-2LP
• Tower — TX1715

12th/13th/14th Gen Intel Core — PCI slots for legacy cards, plus Thunderbolt 4

Expansion: 2x PCIex16 (4.0), 3x PCIex4, 2x PCI

• 4U Rackmount — RX1712-4
• 3U Rackmount — RX1712-3
• 3U Front I/O Rackmount — RX1712-3-FIO
• Tower — TX1712

12th/13th/14th Gen Intel Core — PCIe Gen 5 expansion with Thunderbolt 4

Expansion: 2x PCIex16 (5.0), 2x PCIex4, 3x PCIex1

• 4U Rackmount — RX1714-4

The RX1712 family is the one to look at if your system still relies on conventional PCI cards. It combines two 32-bit PCI slots with modern PCIe expansion and Thunderbolt 4 in the same chassis, which is rare.

Thunderbolt and PCIe Expansion Slots, Together

Thunderbolt connects your computer to external instruments. PCIe and PCI expansion slots connect it to the cards inside. DuroPC computers provide both, so a single system can talk to a Thunderbolt-connected PXI Express chassis while also hosting the data acquisition, motion control, frame grabber, avionics bus, or timing cards your application already depends on.

To see the kinds of expansion cards DuroPC customers have used in our systems, visit Expansion Cards Used by DuroPC Customers.

Why Thunderbolt Is Not Just a Card You Add

It is tempting to assume that any computer with a free PCIe slot can gain Thunderbolt by installing an add-in card. In practice it is not that simple.

A Thunderbolt add-in card does not connect to the computer through the PCIe slot alone. It also needs a dedicated Thunderbolt header on the motherboard, a small multi-pin connector that the card is cabled to. The header is not a universal standard. The card and the motherboard have to be designed to work together, and the board's firmware has to support it. Only a small number of motherboards include it, and most industrial motherboards do not.

What the header does. Thunderbolt is more than a fast data link. The Thunderbolt controller has to coordinate with the computer's chipset and firmware on things that a PCIe slot does not carry, such as recognizing when a device is connected or removed while the system is running (hot-plug), sequencing power, and handling sleep and wake. The header is the sideband connection that carries those control signals between the card and the board. Without it, the card may be physically installed but not fully functional.

DuroPC selects industrial motherboards that include this header, so Thunderbolt works the way it is supposed to. On the RX1715 family, which is built on a newer platform, Thunderbolt 4 ports are provided directly by the board with no add-in card needed.

What Adding Thunderbolt to a Computer Involves

Seeing the steps shows why Thunderbolt is a job for a system builder who has tested the combination. A Thunderbolt card installation has more to it than seating a card in a slot:

• Prepare the computer. Shut it down, unplug the power cord and every other cable, and open the chassis.
• Seat the card. Install the Thunderbolt card in a PCIe slot that the motherboard supports for it. Check the motherboard documentation to choose the right slot.

• Connect the Thunderbolt header cable. One end plugs into the header on the card. The other end plugs into the Thunderbolt connector on the motherboard.

• Connect the internal USB 2.0 cable. A second cable runs from the card to a USB 2.0 header on the motherboard.
• Close up and reconnect. Replace the chassis cover, reconnect the power cord and your other cables, and power on.
• Plug in the Thunderbolt cable. Connect the cable from your instrument or chassis to a Thunderbolt 4 port on the card.

• Enable Thunderbolt in the BIOS. Open the BIOS setup, go to the Advanced menu, find the Thunderbolt option, and turn it on.
• Install the Thunderbolt software in Windows. Use the software supplied with the card.

The card makers add two cautions of their own. These cards follow a reference design, so the motherboard's BIOS and hardware design can affect whether Thunderbolt works, and card makers publish lists of the motherboards they support. Thunderbolt 4 is backward compatible with Thunderbolt 3 cables and devices, but Thunderbolt 2 cables and devices are not supported.

USB-C and Thunderbolt Are Not the Same Thing

Thunderbolt 4 uses the same oval connector as USB-C, so the two are easy to confuse. They are not interchangeable.

• USB-C is a connector. It describes the shape of the plug and port. The data protocol running through a USB-C port can be anything from basic USB 2.0 speeds up to USB4.
• Thunderbolt is a certified protocol that uses the USB-C connector. It requires a Thunderbolt controller and Intel certification, and it guarantees 40 Gbps of bandwidth, PCIe tunneling, DisplayPort video, and higher power delivery.
• PCIe tunneling is the key difference for instrumentation. Thunderbolt carries PCI Express over the cable, so a connected device appears to the computer as if it were installed in a slot. This is what lets a PXI Express chassis, or an external expansion box full of cards, behave like part of the computer.
• Compatibility runs one way. A Thunderbolt port works with USB-C devices. A plain USB-C port does not work with Thunderbolt devices.

Because the connector looks the same either way, check the spec sheet rather than the port. If your test equipment requires Thunderbolt, a USB-C port, even a fast one, will not do the job.

Test and Measurement Equipment That Connects Over Thunderbolt

Thunderbolt has become a standard way to link a computer to modular instrumentation. Examples include:

National Instruments

• PXIe-8301 Thunderbolt 3 PXI Remote Control Module: controls a PXI Express chassis over Thunderbolt 3, with up to 2.3 GB/s of sustained throughput.
• PXIe-1083 chassis: 5-slot, all-hybrid PXI Express chassis with an integrated Thunderbolt 3 MXI-Express controller.
• PXIe-1090 chassis: compact 2-slot PXI Express chassis with an integrated Thunderbolt 3 MXI-Express controller.

ADLINK

• PXES-2314T: 4-slot PXI Express chassis with two Thunderbolt 3 ports.

Other Thunderbolt-connected instrumentation

• MarvinTest GX7980: Thunderbolt remote control module for PXI Express chassis.
• GaGe EON Express and RazorMax Express digitizers: high-speed PCIe digitizers supported through a Thunderbolt 3 PCIe expansion box.

These products use Thunderbolt 3, and Thunderbolt 4 ports are backward compatible with Thunderbolt 3 devices. The NI chassis documentation also notes that the host should run a native, non-virtualized operating system that supports Thunderbolt.

Built Around What Engineers Ask For

DuroPC learns about connectivity needs like Thunderbolt from our customers, then works to implement that connectivity so engineers can get their jobs done. Thunderbolt on a rackmount computer is a good example. Test system builders told us what their instruments required, and we found the motherboards and configurations that deliver it without giving up PCI and PCIe expansion.

Thunderbolt and the Thunderbolt logo are trademarks of Intel Corporation or its subsidiaries. All other product names and trademarks are the property of their respective owners.