PXH840 PCIe NTB Host Adapter

PCI Express Gen3 x16 NTB Host Adapter

The PXH840 PCI Express Gen3 NTB Host Adapter is our high performance optical clustering product. Based on Broadcom® Gen3 PCI Express bridging architecture and Samtec PCIe FireFly® optical engine, the PXH840 NTB host adapter provides advanced features for non-transparent bridging (NTB) over long distance PCIe. The adapter card supports the full Dolphin eXpressWare software stack.

  • One x16 PCIe edge port
  • Two x8/x4 PCIe optical cable ports
  • MTP patch cable
  • 0.54 microsecond latency
  • Low Profile Design
  • Dual MTP connectors
  • Non Transparent Bridging
  • 128 Gigabit/s performance
  • PIO and DMA RDMA
  • Full Dolphin Software Stack

Product Data

The PXH840 Gen3 PCI Express NTB Host Adapter is our high performance optical interface to external processor subsystems. Based on Broadcom® Gen3 PCI Express bridging architecture and Samtec PCIe FireFly® optical engine, the PXH840 host adapter provides advanced features for non-transparent bridging (NTB) over long distance PCIe.

For high performance application developers, the PXH840 host adapter combines 128 Gbit/s performance with an application to application latency starting at 0.54 microseconds. Inter-processor communication benefits from the high throughput and low latency. Using the latest SmartIO technology software from Dolphin, applications can now access PCIe devices located in computers up to 100 metres way as if they was attached to the local system.

The PXH840 performs both Remote Direct Memory Access (RDMA) and Programmed IO (PIO) transfers, effectively supporting both large and small data packets. RDMA transfers result in efficient larger packet transfers and processor off-load exceeding 11 Gigabytes per second. PIO transfers optimize small packet transfers at the lowest latency. The combination of RDMA and PIO creates a highly potent data transfer system.

Dolphin’s software suite takes advantage of PCI Express’ RDMA and PIO data transfer scheme. Delivering a complete deployment environment for customized and standardized applications. The suite includes a Shared-Memory Cluster Interconnect (SISCI) API as well as a TCP/IP driver and SuperSockets software. The SISCI API is a robust and powerful shared memory programming environment.

The optimized TCP/IP driver and SuperSockets™ software remove traditional networking bottlenecks, allowing standard IP and sockets applications to take advantage of the high performance PCI Express interconnect without modification. The overall framework is designed for rapid development of inter-processor communication systems.

The PXH840 card comes with a full license to the Dolphin eXpressWare software. The PXH842 Gen3 Adapter card does not include any software license and is well suited for high performance Transparent IO Expansion applications. The PXH840 card is fully supported in eXpressWare 5.5.0 and newer.

Supported topologies

Using the PXH840 card, you can connect two systems using PCIe Gen3 x4, x8 or x16 depending on the throughput requirements. You can also connect 3 systems using a x8 cable between each system.

Fiber Cables

The PXH840 is carefully designed for maximum cable length and supports fiber cables up to 100 meter optical cables. The x16 configuration requires two MPT female, 24 pairs, OM3 50/125, Key up - Key up (Type C) cables.


  • PCI Express® 3.0 compliant - 8.0 Gbps per lane
  • Slot compliant with Gen1 and Gen2 PCI Express
  • Samtec FireFly optical engine
  • MTP connectors
  • Four x4 Gen3 PCI Express cable ports that can be configured as:
    • One - x16 PCI Express port
    • Two - x8 PCI Express ports
  • Two NTB ports max
  • RDMA support through PIO and DMA
  • Clock isolation support
  • Non-transparent bridging to cabled PCI Express systems
  • Low profile PCI Express form factor
  • EEPROM for custom system configuration
  • Link status LEDs through face plate


PCIe latency over Samtec FireFly fiber PCOA


Feature Description
Link Speeds 32 Gbit/s per port, total 128 Gbit/s
Application Performance 0.54 microsecond latency (application to application)
< 130 nanoseconds cut through latency port to port
Active Components Broadcom / PLX Gen3 PCI Express Switch with DMA
PCI Express®

Base Specification 3.0
Card Electromechanical Specification 3.0

Topologies Point to point or 3 node Mesh Topology
Cable Connections Dual x8 MTP connectors.

Fiber optic cable up to 100 meters
Power Consumption

12 Volt : 14 Watt Max, (typical, 10 Watt without AOC )
+3.3 Volt : Max 3.3 Watt
+3.3 VAUX : Max 1 Watt

Cable Port Power supply

+3.3 Volt +/- 5%, 0.6 A per Cable Port

Mechanical Dimensions Low profile, Half Length - 68.90 mm (2.731 inches) x 167.65 mm (6.600 inches)
Operating Environment Operating Temperature: 0°C - 55°C (32°F - 131°F)
Air Flow: 150 LFM
Relative Humidity: 5% - 95% (non- condensing)
Storage Environment Storage Temperature: -40°C - 70°C (-40°F - 158°F)
Relative Humidity 95% (non- condensing) at 35°C
Software SuperSockets™ Berkley Sockets API
Microsoft WinSock2/LSP support
Advanced TCP/IP driver
PCIe bracket

Full height plate mounted
Half height plate not included, only available for x8 and x4 configurations.

Configuration DIP-switch
NTB / safe boot
Pending Regulatory CE Mark
FCC Class A
RoHS compliant
UL94V-0 compliant
Operating Systems Windows
PXH84x NTB Host card variants
Part Number Installed FireFly devices PCIe configurations
PXH840 2 x8 x16, 2 x8
PXH841 1 x8 x8
PXH843 2 x4 x8, 2 x4
PXH844 1 x4 x4

Dolphin eXpressWare software license included with all NTB variants.