CAPI Compression Accelerator Adapter (FC EJ1A and EJ1B; CCIN 2CF0)

Learn about the specifications and operating system requirements for feature code (FC) EJ1A and EJ1B adapters.


FC EJ1A and EJ1B are both the same adapter with different feature codes. FC EJ1A is a full-height adapter and FC EJ1B is a low-profile adapter. See PCIe3 FPGA Compression Accelerator Adapter (FC EJ12; CCIN 59AB) and PCIe3 FPGA Compression Accelerator Adapter (FC EJ13; CCIN 59AB) for additional compression accelerator adapters.

The PCIe3 CAPI Compression Accelerator Adapter is a PCI Express (PCIe) generation 3 (Gen3) x8 adapter. The adapter can be used in either a x8 or x16 PCIe3 slot in the system. The CAPI Compression Accelerator Adapter implements the well-defined, open standard DEFLATE compressed data format. This data format is widely accepted through zlib, gzip, Java, and other applications. Within the gzip and zip file formats, the adapter is the standard for compressed data exchange. The adapter's high compression bandwidth reduces the latency for a single compression job significantly. Its aggregate throughput allows the adapter to keep pace with common I/O traffic and offers reduced data for storage and network traffic. Additionally, the adapter has no impact on most I/O traffic and in some cases will have a positive effect. The adapter also enables good standard compression in cases where software overhead prevents it. To achieve the best performance gain, strive for data block sizes larger than 64 KB, or combine smaller blocks before sending them to hardware. The accelerated zlib library has a selectable buffering feature built-in as well. For a graphic of the full-height adapter, see Figure 1
Important: Graphics processing units (GPUs) and Coherent Accelerator Processor Interface (CAPI) adapters cannot be replaced with the power on.
The following are examples of typical applications that can benefit from compression acceleration:
  • Store or transmit large amounts of data that average over 100 MB/s
  • Applications that need a high average throughput of data compressed
  • Handling high peak throughput of data when software compression is limited
  • When low latency for individual compression streams is required and it is more difficult to run in parallel on many CPUs
  • When the standard DEFLATE compression format is required for interchange as used in gzip, zlib, zip, or JAR (Software compression methods such as LZ4 or LZS with lower compression ratios and high bandwidth on CPUs are not an option in that case)
  • Compression or a mix of compression and decompression is the main bottleneck (Decompression alone can sometimes still be done in software with many cores in parallel)
    Note: The adapter supports full speed decompression for all compliant compressed input regardless of whether it was compressed by hardware or software.

For details about slot priorities and placement rules, see PCIe adapter placement rules and slot priorities and select the system you are working on.

Figure 1. CAPI Compression Accelerator Adapter (Full-height)
CAPI Compression Accelerator Adapter (Full-height)


Adapter FRU number
00WT173 (Designed to comply with RoHS requirement)
I/O bus architecture
PCIe3 x8
Slot requirement
One PCIe x8 or x16 CAPI enabled slot per adapter
Supported Systems
POWER8® processor-based server
  • 8247-21L, 8247-22L, and 8247-42L
  • 8335-GCA and 8335-GTA
  • 8348-21C
12 V
Form factor
Short, with full-height tailstock (FC EJ1A)
Short, low-profile (FC EJ1B)
Maximum number
For details about the maximum number of adapters that are supported, see PCIe adapter placement rules and slot priorities and select the system you are working on.
Attributes provided
High throughput compression that saves storage and I/O bandwidth with little or no overhead
CPU offload and CAPI interface with negligible software load frees up CPU cores for higher value computation or licensed software
Lower power consumption by offloading the CPU intensive compression to an FPGA
Widely used zlib and gzip standard format for data interchange
Up to 2 GB/s compression and decompression throughput
4-30x speed up achievable
Compression ratio near software zlib and gzip
Multiple uses including genomics, data center, cloud, and backup solutions

Operating system or partition requirements

If you are installing a new feature, ensure that you have the software that is required to support the new feature and that you determine whether any prerequisites must be met for this feature and attaching devices. To check for the prerequisites, see IBM® Prerequisite website.

The adapter is supported on the following versions of the operating systems:
  • Linux
    • Red Hat Enterprise Linux 7.2 LE, or later
    • Ubuntu 14.04.5, or later
    • For support details, see the Linux Alert website.
    • For additional information regarding firmware level and additional software installations, see Fix Central.
    • To use the CAPI Compression Accelerator Adapter, the following software packages must be downloaded at the IBM Service and Productivity Tools website:
      • genwqe-zlib: Hardware accelerated zlib
      • genwqe-tools: Tools to analyze adapter functionality plus hardware accelerated genwqe_gzip and genwqe_gunzip
    • For details on how the adapter can be used to accelerate your application, please refer to the CAPI Compression Accelerator Adapter user’s guide published on IBM developerWorks .

Last updated: Thu, June 27, 2019