MXH915 Transparent Host Adapter

Gen4 x4 PCIe Transparent Host Adapter

The MXH915 Transparent Host Adapter is our entry level PCIe 4.0 IO product. Based on Microchip Switchtec Gen4 PCI Express bridging architecture, the MXH915 Adapter includes advanced features for PCIe 4.0 transparent bridging and clock isolation.

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

Product Data

The MXH915 Gen4 Host Adapter is our entry level PCIe 4.0 solution for connecting servers to external I/O subsystems. Based on Microchip® Gen4.0 PCI Express bridging architecture, the MXH915 adapter enables reliable transparent PCIe cable connections and clock isolation.


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 MXH915 is carefully designed for maximum cable lengths. Fiber optics extends this distance to 100 meters. More info on cable alternatives for the MXH932 card.


The MXH915 uses an on-board DIP-Switch to select operational parameters.

eXpressWare Board Management Software

The MXH915 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® 4.0 compliant - 16.0 GT/s per lane
  • Link compliant with Gen1, Gen2, Gen3, and  Gen4 PCI Express
  • PCIe 4.0 cables
  • Single SFF-8644 x4 Gen4 PCI Express cable port that can be configured as one x4 link.
  • 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 Gen4 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 Gbit/s per port, total 256 Gbit/s
Cut through latency 100 nanoseconds
Active Components Microchip Switchtec® Gen4 PCI Express Switch
PCI Express® Base Specification4.0
External Cabling Specification Spec 4.0

One x4 connection

Switch topologies using MXS924

Cable Port Single SFF-8644 / x4 Gen4 Port
Supported cables

PCIe 4.0 cables
PCIe 4.0 fiber optic cables

Maximum power rating

12 Volt: max 1.49A (no port power) - 1.62A (max port power)
+3.3 Volt: Not connected
+3.3 Volt Aux: 0.03A

Typical power rating

12 Volt: 1.0A (no port power)
+3.3 Volt: Not connected
+3.3 Volt Aux: 0.01A

Port power supply

VPWR: 3.2V - 3.4V, 0.455A
VMGTPWR: 3.2V - 3.4V, 0.30mA

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 (@max ambient temperature)
Relative Humidity: 5% - 95% (non- condensing)
Software No software needed
Configuration DIP-Switch
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

MXH914 - NTB Host + Transparent Host functionality Dolphin eXpressWare software license

MXH915 - Transparent Host functionality only

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