Lossless data compression is highly desirable in enterprise and cloud environments for storage and memory cost savings and improved utilization I/O and network. While the value provided by compression is recognized, its application in practice is often limited because it's a processor intensive operation resulting low throughput and high elapsed time for compression intense workloads.The IBM POWER9 and IBM z15 systems overcome the shortcomings of existing approaches by including a novel on-chip integrated data compression accelerator. The accelerator reduces processor cycles, I/O traffic, memory and storage footprint of many applications practically with zero hardware cost. The accelerator also eliminates the cost and I/O slots that would have been necessary with FPGA/ASIC based compression adapters. On the POWER9 chip, a single accelerator uses less than 0.5% of the processor chip area, but provides a 388x speedup factor over the zlib compression software running on a general-purpose core and provides a 13x speedup factor over the entire chip of cores. On a POWER9 system, the accelerators provide an end-to-end 23% speedup to Apache Spark TPC-DS workload compared to the software baseline. The z15 chip doubles the compression rate of POWER9 resulting in even much higher speedup factors over the compression software running on general-purpose cores. On a maximally configured z15 system topology, on-chip compression accelerators provide up to 280 GB/s data compression rate, the highest in the industry. Overall, the on-chip accelerators significantly advance the state of the art in terms of area, throughput, latency, compression ratio, reduced processor utilization, power/energy efficiency, and integration into the system stack.This paper describes the architecture, and novel elements of the POWER9 and z15 compression/decompression accelerators with emphasis on trade-offs that made the on-chip implementation possible.

A device capable of executing interlocked fixed point arithmetic logic unit (ALU) instructions in parallel with other instructions causing the execution interlock is presented. The device incorporates the design of a 3-1 ALU and can execute two's complement, unsigned binary, and binary logical operations. It is shown that status for ALU operations using a 3-1 ALU can be determined in a parallel fashion, resulting in the compliance of the proposed device with predetermined architectural behavior of single instruction execution. The device requires no more logic stages than does a 3-1 binary adder using a carry-save adder (CSA) followed by a carry-lookahead adder (CLA) design. Design considerations using a commonly available CMOS technology are also reported, indicating that the device will not increase the machine cycle of an implementation. It is suggested that the device can maintain full architectural compatibility.>