High-Performance Hardware Merge Sorter

State-of-the-art studies show that FPGA-based hardware merge sorters (HMSs) can achieve superior performance compared with optimized algorithms on CPUs and GPUs. The performance of any HMS is proportional to its operating frequency (F) and the number of records that can be output each cycle (E). However, all existing HMSs have a problem that F drops significantly with increasing E due to the increase of the number of levels of gates. In this paper, we propose novel architectures for HMSs where the number of levels of gates is constant when E is increased. We implement some HMSs adopting the proposed architectures on a Virtex-7 FPGA. The evaluation shows that an HMS of E = 32 operates at 311MHz and achieves 3.13x higher throughput than the state-of-the-art HMS.