COM-HPC specification makes progress
COM-HPC will increase memory and performance compared with COM Express (COM Express image – congatec)
As the industry prepares for the computing demands of increased connectivity in vehicles, factories and homes, the PCI Industrial Computer Manufacturers Group (PICMG) is able to provide an update on the standard computer on module (COM) standard that will provide the scalable performance and connectivity required.
The COM-HPC standard is expected to be released later this year and brings some significant performance upgrades compared with COM Express. It is the fastest COM standard yet and is being developed specifically to meet the performance needs of new applications, such as AI, 5G and extensive edge computing. Modules will be divided into server and client types.
The COM-HPC server is a headless module, principally for use in edge servers, where a lot of data is communicated and interpreted, for AI and analytics.
The COM-HPC client is similar to COM Express, said congatec’s Christian Eder, but with higher performance and more memory, for use in high end, more conventional embedded markets.
The client type will include two MIPI-CSI (Mobile Industry Processor Interface – Camera Serial Interface) to handle the imaging tasks demanded by surveillance camera systems, medical equipment and autonomous vehicles.
Characteristics
Most significant of these is the increase in RAM, COM-HPC server modules will have up to 1Tbyte by virtue of eight DIMM sockets on the board.
There will be a near-doubling of pins in this specification – 800 compared with 440 for COM Express.
COM-HPC server modules will also support up to eight 25GbE lanes and up to 64 PCIe Gen 4 or Gen 5 lanes, for a performance of up to 255GBps. There will also be two USB 4 interfaces which, at 40Gbps will nearly double the rates of USB 3.2.
Eder, is chairman of the COM-HPC committee. He told Electronics Weekly that there is a lot of work being done to prepare for ratification of the standard in the first half of 2020.
“These are very intense times. . . the first milestone was to have a specification where companies can really start to develop designs. This means all the mechanics, with lots of sizes, what connector, what is the pin-out of that connector,” he said.
At this date, the specification is not complete but “good enough” for specialists to begin planning development of the next generation of high speed embedded systems. A lot of documentation is still required, conceded Eder, and the 24 members are working on that.
The COM-HPC connector is specified today for PCI Express Gen 5 and Eder says there is a “high probability” that it will support PCI Express Gen 6, which is still to be released.
It is also 10G/25G Ethernet-compliant and operates at up to 300W at 11.4V to 12.6V. Although there are no benchmarks to date, conceded Eder, it means that faster CPUs can be supported than is possible today.
The high-density connectors use a BGA termination for alignment and is available in two stack heights of 5mm and 10mm.
Signal integrity
Interface revisions included in the specification are the used of an Edge Rate contact system to minimise broadside coupling and reduce crosstalk.
A sub group will focus on signal integrity, defining routing rules, while another will define the software stack required for management functionalities for the server role.
Power consumption has also increased to 300W – COM Express is 60W maximum – to support faster CPUs.
Embedded Application Programming Interfaces (APIs), introduced with COM Express, allow unified access to a selection of interfaces, including I2C and UART.
Modules can be exchanged for upgrades or to change technologies from one chip vendor or module supplier to another. Developers can offer edge server functions, such as boot options, via board management controller.
Congatec at Embedded World 2020: Hall 1-358
Figure 1: COM-HPC will increase memory and performance compared with COM Express (COM Express image – congatec)
Table 1 – The features of COM-HPC client and server types