The data deluge in medical imaging processing requires faster and more efficient systems. Due to the advance in recent heterogeneous architecture, there has been a resurgence in research aimed at domain-specific accelerators. In this article, we develop an experimental system SuperDragon for evaluating acceleration of a single-particle Cryo-electron microscopy (Cryo-EM) 3D reconstruction package EMAN through a hybrid of CPU, GPU, and FPGA parallel architecture. Based on a comprehensive workload characterization, we exploit multigrained parallelism in the Cryo-EM 3D reconstruction algorithm and investigate a proper computational mapping to the underlying heterogeneous architecture. The package is restructured with task-level (MPI), thread-level (OpenMP), and data-level (GPU and FPGA) parallelism. Especially, the proposed FPGA accelerator is a stream architecture that emphasizes the importance of optimizing computing dominated data access patterns. Besides, the configurable computing streams are constructed by arranging the hardware modules and bypassing channels to form a linear deep pipeline. Compared to the multicore (six-core) program, the GPU and FPGA implementations achieve speedups of 8.4 and 2.25 times in execution time while improving power efficiency by factors of 7.2 and 14.2, respectively.

The explosion of Next Generation Sequencing (NGS) data with over one billion reads per day poses a great challenge to the capability of current computing systems. In this paper, we proposed a CPU-FPGA heterogeneous architecture for accelerating a short reads mapping algorithm, which was built upon the concept of hash-index. In particular, by extracting and mapping the most time-consuming and basic operations to specialized processing elements (PEs), our new algorithm is favorable to efficient acceleration on FPGAs. The proposed architecture is implemented and evaluated on a customized FPGA accelerator card with a Xilinx Virtex5 LX330 FPGA resided. Limited by available data transfer bandwidth, our NGS mapping accelerator, which operates at 175MHz, integrates up to 100 PEs. Compared to an Intel six-cores CPU, the speedup of our accelerator ranges from 22.2 times to 42.9 times.

The wide acceptance of bioinformatics, medical imaging and multimedia applications, which have a data-centric favor to them, require more efficient and application-specific systems to be built. Due to the advances in modern FPGA technologies recently, there has been a resurgence in research aimed at accelerator design that leverages FPGAs to accelerate large-scale scientific applications. In this paper, we exploit this trend towards FPGA-based accelerator design and provide a proof-of-concept and comprehensive case study on FPGA-based accelerator design for a single-particle 3D reconstruction application in single-precision floating-point format. The proposed stream architecture is built by first offloading computing-intensive software kernels to dedicated hardware modules, which emphasizes the importance of optimizing computing dominated data access patterns. Then configurable computing streams are constructed by arranging the hardware modules and bypass channels to form a linear deep pipeline. The efficiency of the proposed stream architecture is justified by the reported 2.54 times speedup over a 4-cores CPU. In terms of power efficiency, our FPGA-based accelerator introduces a 7.33 and 3.4 times improvement over a 4-cores CPU and an up-to-date GPU device, respectively.

Over the past decades, we noticed huge advances in FPGA technologies. The topic of floating-point accelerator on FPGA has gained renewed interests due to the increased device size and the emergence of fast hardware floating-point library. The popularity of FFT makes it easier to justify spending lots of effort doing detailed optimization. However, the ever increasing data size in some compelling application domains remains beyond the capability of existing FFT accelerators. The demand for more performance remains an active research topic. In this paper, leveraging structured description of FFT algorithms, we propose a FPGA-based FFT core generation framework, which emits Verilog HDL code given high-level algorithmic description and can handle radix-2 as well as prime-radix problem size. In particular, the proposed framework is optimized for 2D FFT and real FFT. The performance of our implementation is comparable with a commercial FFT IP. When compared with the latest results on GPU and CPU, measured in peak floating-point performance and energy efficiency, it shows that GPUs have outperformed FPGAs for FFT acceleration. However, we consider that FPGAs still have advantage in some situations.

BACKGROUND: The emerging next-generation sequencing method based on PCR technology boosts genome sequencing speed considerably, the expense is also get decreased. It has been utilized to address a broad range of bioinformatics problems. Limited by reliable output sequence length of next-generation sequencing technologies, we are confined to study gene fragments with 30 - 50 bps in general and it is relatively shorter than traditional gene fragment length. Anchoring gene fragments in long reference sequence is an essential and prerequisite step for further assembly and analysis works. Due to the sheer number of fragments produced by next-generation sequencing technologies and the huge size of reference sequences, anchoring would rapidly becoming a computational bottleneck. RESULTS AND DISCUSSION: We compared algorithm efficiency on BLAT, SOAP and EMBF. The efficiency is defined as the count of total output results divided by time consumed to retrieve them. The data show that our algorithm EMBF have 3 - 4 times efficiency advantage over SOAP, and at least 150 times over BLAT. Moreover, when the reference sequence size is increased, the efficiency of SOAP will get degraded as far as 30%, while EMBF have preferable increasing tendency. CONCLUSION: In conclusion, we deem that EMBF is more suitable for short fragment anchoring problem where result completeness and accuracy is predominant and the reference sequences are relatively large.