PCIe Host & Target Adapters

Create the physical and logical bridge between a host, a remote device domain or another computer while choosing transparent access or isolated NTB communication.

PCIe generations

Gen3 · Gen4 · Gen5

Link widths

x4 · x8 · x16

Modes

Transparent · NTB

Media

Copper · optical

Host adapters Target adapters NTB SFF-8614 SFF-8644 FireFly / CopprLink

Technical context: Dolphin MXH and related adapter families cover transparent host/target and NTB roles across selected PCIe generations. Lane aggregation, cable interface, clock isolation and eXpressWare support are model-specific. Selected Gen5 FireFly and CopprLink variants remain preliminary or availability-controlled; confirm the exact adapter, firmware and cable set before design-in.

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System Capabilities

Host and target adapters define whether a system extends one PCIe hierarchy or connects independent computers through NTB communication.

Transparent remote-device access

Extend one host to compatible external endpoints while retaining supported PCIe drivers.

Independent-host communication

Connect separate computers through NTB without combining their boot and address domains.

Workload-matched links

Select PCIe generation, lane width and media according to the required sustained traffic and installation distance.

Direct or switched deployment

Use the same adapter roles in point-to-point expansion or larger managed fabrics through compatible MXS524, MXS924 or MXS824 switch platforms.

Technical Features

Key platform elements and integration considerations are outlined below.

PCIe 5.0 families

MXH530/MXH532 use quad SFF-8614 ports, while MXH570/MXH572 use a single x16 CDFP CopprLink interface. The MXH540/MXH542 FireFly optical family provides MPO-connected Gen5 links up to 100 m. Selected Gen5 CopprLink and FireFly variants are published as preliminary or availability-controlled, so orderability and the final cable set must be confirmed.

PCIe 4.0 families

MXH930/MXH932 provide x16 Gen4 SFF-8644 connectivity, while MXH940/MXH942 use FireFly optical engines. Additional x4 and x8 Gen4 models support narrower or fan-out topologies.

PCIe 3.0 continuity

MXH and PXH families support deployed Gen3 systems, including standard PCIe and selected embedded form factors.

Transparent host and target roles

A transparent host adapter extends one root complex to compatible remote endpoints. The target side terminates the link and remains under the host's enumeration domain.

NTB host-to-host networking

NTB adapters keep root complexes independent and provide translated memory windows, DMA, interrupts and eXpressWare software interfaces.

Clock isolation and cabling

Supported adapters isolate host and cable clocks. The selected connector, media and lane mapping must match at both ends of the link.

Specifications

Technical parameters and system-integration requirements are listed below.

PCIe Host & Target Adapters architecture and integration parameters
Parameter	Unit	Value / Description
ADAPTER ARCHITECTURE
Operation mode	—	Transparent host/target expansion or NTB host-to-host networking.
PCIe generations	—	Gen3, Gen4 and Gen5 product families.
Host edge width	lanes	x4, x8 or x16 depending on model.
Cable ports	—	One or more x4 links aggregated as x8 or x16, depending on adapter.
PHYSICAL INTERFACES
Gen5 copper	—	SFF-8614 with four x4 ports, or CDFP CopprLink with one x16 port; current passive-copper reach is up to 3 m.
Gen5 optical	—	FireFly optical engines with MPO connectors on selected adapters; Gen5 reach up to 100 m and selected Gen4 reach up to 200 m.
Gen4 / Gen3	—	SFF-8644 copper up to 5 m, SFF-8644 active optical up to 100 m, FireFly optical up to 200 m on selected Gen4 models, plus legacy iPass interfaces.
Form factors	—	Standard PCIe cards plus selected XMC, PXIe and CompactPCI Serial implementations.
SYSTEM FIT
Endpoint compatibility	—	Driver, BAR size, reset, hot-plug and peer-to-peer behaviour must work through the selected topology.
Host resources	—	BIOS enumeration and MMIO allocation can limit large GPUs, FPGAs and multi-device systems.
Software	—	Transparent links use supported native endpoint drivers and Dolphin board-management software; NTB operation uses compatible eXpressWare components and licensing.
Performance	—	Negotiated generation, width, cable media and switch hops determine available bandwidth and latency.

Applications

The architecture is most useful where native PCIe access, sustained data movement or tightly coupled multi-node communication materially affects the system.

HPC and AI

Connect independent compute nodes with NTB adapters or extend GPUs and storage transparently from a controlling host.

Test and measurement

Place digitizers, FPGA cards and instrument interfaces outside the controller while retaining compatible native drivers.

Aerospace and defence

Build cabled PCIe links among servers, embedded computers, PXIe and CompactPCI Serial platforms in system-qualified installations.

Automotive development

Interconnect HIL, logging and sensor-processing platforms for laboratory validation and high-rate data workflows.

Medical and scientific imaging

Separate acquisition and acceleration cards from compact operator systems while maintaining a high-bandwidth device path.

Low-latency server communication

Use NTB fabrics with SISCI, SuperSockets or IPoPCIe for tightly coupled applications in a controlled local environment.