IBM - Coherent Accelerator Processor Interface (CAPI)

POWER8 Coherent Accelerator Processor Interface (CAPI)

Tab navigation


In today's high performance compute environments, acceleration of algorithms is key to meeting end customers' service requirements. Acceleration can deliver both higher performance and lower cost, but only if the compute platform is designed for heterogeneous computing. The IBM POWER8® chip, with its Coherent Accelerator Processor Interface (CAPI) technology, delivers on this promise of accelerated computing.

Whether the workload is on the premises or in the cloud, IT organizations must provide increased system performance as their workloads grow with demands for big data analysis, social media applications, continuous customer connectivity, and business-specific applications. Increases in processor performance alone cannot satisfy the workload demands. Therefore, solutions must also come from system-level advances such as heterogeneous computing, processing engine customization, and open platform development that enables cross-company innovation.

CAPI connects a custom acceleration engine to the coherent fabric of the POWER8 chip. The hybrid solution has a simple programming paradigm while delivering performance well beyond today's I/O-attached acceleration engines.

With many accelerators now available, solution providers are using CAPI to improve performance versus existing solutions, to lower costs, and to create solutions that were previously beyond the reach of the compute complex.

CAPI description

CAPI on POWER8 systems provides a high-performance solution for the implementation of software-specific, computation-heavy algorithms on an FPGA. This innovation can replace either application programs running on a core or custom acceleration implementations attached via I/O. CAPI removes the overhead and complexity of the I/O subsystem, allowing an accelerator to operate as an extention of an application. The IBM solution enables higher system performance with a much smaller programming investment, allowing heterogeneous computing to be successful across a much broader range of applications.

Power Systems Assistance

Because the FPGAs are reconfigured, hardware can be specialized without the traditional costs of hardware fabrication. CAPI enables a customer-defined FPGA solution to be a peer to the POWER8 cores from a memory access (coherent) standpoint.

CAPI white papers

For more information about CAPI and for CAPI use cases, see:

Contact IBM

Power Systems Assistance

Purchase a CAPI Developer Kit

Available through OpenPOWER Foundation partners, Nallatech and Alpha-Data

Translate this page