COM-HPC is an open standard for embedded computing modules that supports server-class bandwidth, power, and performance. COM-HPC modules come in various sizes and configurations suitable for high-end IoT and edge server applications. Ratified in 2021, COM-HPC solutions are available from over a dozen suppliers worldwide.
On this Page
- Key Features and Benefits
- New Features in COM-HPC
- COM-HPC Module Classes
- Module Sizes
- Module Connectors
- FuSa and OOB Features
- Power Ratings
- Related Documents
- COM-HPC Products from our Members
Key Features and Benefits
COM-HPC is a computer-on-module (COM) specification for high-performance computing (HPC). it provides a two-board architecture consisting of:
- A standardized compute module that contains processor(s), memory, and other core logic
- A customizable carrier board that can be configured to meet a variety of application-specific requirements
- A module connector that physically attaches the module to the board and provides high-speed, high-pin count signaling between the two.
The modular design streamlines the creation of custom hardware while also ensuring upgradability of the processor and memory subsystems. This design methodology has been proven by the longstanding success of COM Express, a COM specification ratified by PICMG in 2005.
Typical COM-HPC modules
As an open standard, COM-HPC circumvents concerns about vendor lock-in and ensures design longevity. Dozens of COM-HPC solutions are already available, and this number is likely to grow, as evidenced by the hundreds of solutions available for the well-established COM Express standard.
New Features in COM-HPC
COM-HPC complements COM Express by extending performance and feature sets for more demanding and emerging applications. Key new features include:
- Larger module sizes, up to 200 mm x 160 mm
- Higher power budgets up to 300 W
- Support for server-class processors with power budgets of 300+ W
- Higher memory capacity, up to 1 TB
- Higher-bandwidth interfaces including PCI Express Gen 5, USB4, DisplayPort 2.0, and 25G Ethernet
- Functional safety (FuSa) and out-of-band (OOB) management extensions
Combined with high-bandwidth interface support, the increased power envelope enables the use of high-performance heterogeneous multicore SoCs with up to 150W power dissipation. COM-HPC modules may host x86 systems, ARM or RISC CPUs, or GPUs, FPGAs, accelerators, or other PCIe targets.
COM-HPC Module Classes
The base COM-HPC specification defines two pinout types: COM-HPC Server and COM-HPC Client. Each calls for a pair of 400-pin connectors that support up to 65 PCIe 5.0 lanes that deliver 32 Gbps throughput, as many as eight 25 GbE channels, 40 Gbps USB4/Thunderbolt data transfer speeds, 80 Gbps DisplayPort signals, and more.
The COM-HPC 1.2 specification introduced a more compact Client form factor, COM-HPC Mini, which removes one of the 400-pin connectors but retains the other to support PCIe 5.0, 25 GbE, USB4, and other high-bandwidth interfaces.
COM-HPC pinouts
Server Module
COM-HPC Server targets headless (no display) embedded servers that require intensive CPU performance, large memory capacity, and high bandwidth I/O. Typical uses are in rugged servers in field environments and applications such as autonomous vehicles, cell tower base stations, geophysical field equipment, medical equipment, and defense systems.
Server modules typically use full-size DIMMs. Up to eight full-size DIMM memories may be implemented on the largest COM-HPC module form factor.
I/O includes multiple 10 Gbps or 25 Gbps Ethernet, and up to 65 PCIe lanes at up to PCIe Gen 5 speeds.
Client Module
COM-HPC Client targets high-end embedded Client products that need one or more displays, a full set of low-, medium-, and very-high-bandwidth I/O, powerful CPUs, and a modest form factor. Typical include medical equipment, high-end instrumentation, industrial equipment, casino gaming equipment, ruggedized field PCs, transportation, and defense systems.
Client modules typically contain soldered-down or SO-DIMM memory, with a capacity for up to four SO-DIMM slots.
I/O includes multiple 10 Gbps or 25 Gbps Ethernet, and up to 49 PCIe lanes at up to PCIe Gen 5 speeds.
Mini Module
COM-HPC Client targets applications that can benefit from the cutting-edge features of COM-HPC but have smaller footprint, power, and cost constraints. It uses a smaller board size than the Client and Server Modules and only a single 400-pin connector.
Like its larger siblings, COM-HPC Mini supports high-bandwidth interfaces including USB 4.0, Thunderbolt, PCIe Gen 5, and 10 Gbit/s Ethernet. However, the reduced pin count necessitates pin sharing for some functions. For example, the same pins are used for either USB 4.0, or for DDI and USB 3.2 interfaces.
At the same time, the Mini form factor adds some interfaces that are common in small form factor applications, such as a CAN bus, two SGMII ports, and an extra I2C port for the SGMII ports. The Mini also adjusts many I/O voltage rails from 3.3V to 1.8V for lower power consumption and increased efficiency.
A unique aspect of the COM-HPC Mini is its reduced overall height from the top of the carrier board to the top of a heat spreader on the module, which is specified as 15 mm. This is a 5 mm reduction compared to other COM-HPC variants. This reduction in height necessitates the use of soldered memory for COM-HPC Mini modules to ensure ruggedness and direct thermal coupling to heat spreaders, accommodating the form factor’s smaller size and reduced stack height.
Module Sizes
Six COM-HPC module sizes are defined. COM-HPC Server modules are typically larger than the Client modules, but Server vendors are free to use any of the defined COM-HPC module sizes.
COM-HPC module sizes
Module Connectors
COM-HPC uses 400-pin high-performance connectors. The Mini size uses a single connector; all other sizes use two connectors for a total of 800 pins. The connectors support signaling rates up to 32 Gbps, suitable for PCIe Gen 5. The connector system allows for 5 or 10 mm carrier/module stack heights.
COM-HPC module connectors
FuSa and OOB Features
The COM-HPC 1.15 Functional Safety (FuSa) sub-specification defines an additional SPI interface dedicated to communication between safety blocks on host processors and a safety controller located on carrier cards to extend status and health monitoring capabilities to the entire COM-HPC-based system.
COM-HPC module and carrier boards may also support OOB management features. These features may be implemented on COM-HPC Server or Client systems. While the specification provides a ramp to data center-class performance and the option for IT/networking features like OOB management, it also retains technologies expected in an embedded edge device including UART, I2C, SPI/eSPI, and USB 2.0 serial interfaces across all pinouts.
Power Ratings
By default, all COM-HPC modules operate from a fixed 12 V power source over 28 VCC pins. Client and mini-modules may optionally operate from a range of input supply voltages from 8-20 V. This power supply flexibility allows Client and mini-modules to be used in battery-powered equipment.
Server modules can accept up to 358 W of input power at the low end of the 12 V power range. This allows CPUs with about 150 W dissipation to be deployed on Server modules.
Client modules can accept up to 251 W of input power at the 8 V end of the power range. This allows CPUs with about 150 W dissipation to be deployed on Server modules. Higher power operation is possible if the fixed 12 V supply operation is used.
Mini modules can accept up to 107 W of input power at the 8 V end of the power range.
For all modules, power limits are subject to considerations such as the connector pin derating (typically 20%), the number of memory sockets used, and other power consumers on the module.
Related Documents
- Abridged COM-HPC module Base Specification
- COM-HPC Carrier Design Guide
- Embedded EEPROM specification for COM-HPC
- EAPI (Embedded Application Programming Interface)
- Platform Management Interface Specification
- COM-HPC Logos
