MXH919 Transparent Host Adapter

PCIe 4.0 x8 Transparent Host Adapter

The MXH919 PCIe 4.0 x8 Transparent Host Adapter is our medium performance PCIe 4.0 IO product. It is based on the Microchip Switchtec PCIe 4.0 chipset and is ideal for transparent IO and clock isolation.

  • One x8 PCIe edge port
  • Two x4 PCIe Cable ports
  • PCIe 4.0 cables
  • Copper and Fiber cable support
  • Quad SFF-8644 Connectors
  • Host Transparent Bridging
  • Low Profile Design
  • Optional board management software

Product Data

The MXH919 PCIe 4.0 Host Adapter is our medium performance transparent solution for connecting servers to external I/O subsystems. Based on Microchip® Gen4.0 PCI Express bridging architecture, the MXH919 adapter enables reliable transparent PCIe cable connections and clock isolation. The MXH919 has a PCIe 4.0 x8 Edge connector and two PCIe Gen 4.0 x4 SSF-8644 connectors and is typically recommended for fan-out where sustained PCIe Gen 4.0 x16 performance is not needed.

For high performance application, such as GPU farms, test and measurement equipment, medical equipment, and storage subsystem we recommend the MXH932 card.


The card does not supports the new PCI-SIG CMI (Cable Management Interface ) protocol as defined in the current PCI-SIG External Cable specification 3.0 but uses a proprietary mechanism to transmit reset. Please contact Dolphin for more information on compatibility for PCIe target devices. If you need a transparent card with Host and Target functionality supporting the CMI protocol, please select the MXH932.


The MXH919 card has a dual SFF-8644 cable connector and supports PCIe 4.0 cables and is carefully designed for maximum cable lengths. Fiber optics extends this distance to 100 meters. More info on cable alternatives for the MXH919 card.


The MXH919 uses an on-board DIP-Switch to select operational parameters. The adapter cable port can be configured as two x4 or one x8 PCIe connection. The card does not support being used as a Transparent Target card. Please select the MXH932.if you need a card supporting Transparent Target operation.

eXpressWare Board Management Software

The MXH919 Adapter card comes with the optional eXpressWare Board Management software for simplified monitoring and management. For more information on Dolphin board management software visit here.

PCI Express NTB

The MXH919 card is a transparent Host product only. To utilize the Dolphin's PCIe NTB eXpressWare clustering software, you need to purchase the MXH918 PCIe 4.0 NTB adapter card.


  • PCI Express® 4.0 compliant - 16.0 GT/s per lane
  • Link compliant with Gen1, Gen2, Gen3 and   Gen4 PCI Express
  • PCIe Gen 4.0 x8 Edge connector
  • PCIe 4.0 cables
  • Dual SFF-8644 x4 Gen4 PCI Express cable ports that can be configured as:
    • One - x8 PCI Express port
    • Two - x4 PCI Express ports
  • Supports both copper and fiber-optic cables
  • Host clock isolation support
  • Low profile PCI Express form factor
  • Flash for safe system configuration
  • Link status LEDs through face plate

Dolphin PCIe 4.0 Transparent Adapter comparison

The table below compares the PCIe Gen 4.Transparent adapters available from Dolphin.

Adapter PCIe Edge PCIe Cable port Host/Target CMI
MXH932 x16 Quad x4 SFF-8644 Host/Target Yes
MXH919 x8 Dual x4 SFF-8644 Host No
MXH917 x8 Quad x4 SFF-8644 Host No
MXH915 x8 Single x4 SFF-8644 Host No


Feature Description
Link Speeds 64 GT/s per port, total 128 GT/s
Cut through latency 100 nanoseconds
Active Components Microchip Switchtec® Gen4 PCI Express Switch
PCI Express® Base Specification4.0

One x8 connection
Two x4 connections

Switch topologies using MXS924

Cable Port Dual SFF-8644 / Two x4 Gen4 Ports
Supported cables

PCIe 4.0 cables
PCIe 4.0 fiber optic cables

Maximum power rating 12 Volt: max 1.66A (no port power) 2.86A (max port power)
+3.3 Volt: Not connected
+3.3 Volt Aux: max 100mA
Typical power rating 12 Volt: 1.5 A (no port power)
+3.3 Volt: Not connected
+3.3 Volt Aux: max 100mA
PCIe Bracket Full height plate mounted
Half height plate included
Mechanical Dimensions Low profile, Half length 167.65mm- (6.6 inches) x 68.90 mm (2.731 inches)
Operating Environment Operating Temperature: 0°C - 55°C (32°F - 131°F)
Airflow : 350 LFM (Preliminary)
Relative Humidity: 5% - 95% (non- condensing)
Software No software needed
Configuration DIP-Switch
Host x4, x8, x16 Link, safe boot
Regulatory approvals CE Mark
FCC Class A
RoHS compliant
UL94V-0 compliant
Regulatory EMC tests EN 55032:2012
EN 55035:2017
EN 61000-3-2:2014
EN 61000-3-3:2013
47 CFR Part 15, Subpart B (Clause 15.107 and 15.109) in conjunction with ANSI C63.4:2014
CISPR 35:2016 Edition 1.0 (CISPR/I/412/CDV) Korean Harmonized standard, KN 35
Operating Systems Basic operations - All

MXH919 - Transparent Host functionality only

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