FPGAs are drawing increasing attention in resolving molecular dynamics (MD) problems, and have already been applied in problems such as two-body potentials, force fields composed of these potentials, etc. Competitive performance is obtained compared with traditional counterparts such as CPUs and GPUs. However, as far as we know, FPGA solutions for more complex and real-world MD problems, such as multi-body potentials, are seldom to be seen. This work explores the prospects of state-of-the-art FPGAs in accelerating multi-body potential. An FPGA-based accelerator with customized parallel dataflow that features multi-body potential computation, motion update, and internode communication is designed. Major contributions include: (1) parallelization applied at different levels of the accelerator; (2) an optimized dataflow mixing atom-level pipeline and cell-level pipeline to achieve high throughput; (3) a mixed-precision method using different precision at different stages of simulations; and (4) a communication-efficient method for internode communication. Experiments show that, our single-node accelerator is over 2.7× faster than an 8-core CPU design, performing 20.501 ns/day on a 55,296-atom system for theTersoffsimulation. Regarding power efficiency, our accelerator is 28.9× higher than I7-11700 and 4.8× higher than RTX 3090 when running the same test case.

Virtual machines (VMs) heavily rely on virtual CPUs (vCPUs) scheduling to achieve efficient I/O performance. The vCPU scheduling interference can cause inconsistent scheduling latency and degraded I/O performance, potentially compromising the services provided by affected VMs. Existing solutions have limitations, such as inefficiency in diagnosing interference issues or imposing undesired side effects on cloud systems. To address these challenges, we present Otter, a holistic technique for optimizing I/O performance in the presence of vCPU scheduling interference. Otter employs innovative methods to enhance interference diagnosis efficiency. First, we propose lightweight methods to measure the dynamic changes in scheduling latencies for co-running vCPUs, ensuring both flexibility and accuracy. Second, we propose fine-grained quantification methods to timely determine the interference, with low false positive and false negative rates. Third, we identify interference patterns that aid in analyzing the root causes of interference and preventing similar issues from recurring. Otter has been operational for one year in the production cloud at the National Supercomputing Center (Wuxi). It diagnoses and helps fix more than 470 vCPU scheduling interference-related issues, resulting in a 19.6% improvement in cloud service I/O performance with negligible overhead in production.

The Community Atmosphere Model (CAM) has been ported, redesigned, and scaled to the full system of the Sunway TaihuLight, and provides peta-scale climate modeling performance. Based on a novel domain decomposition method, we have fully optimized the complete model code by using both OpenACC refactoring and more aggressive and finer-grained Athread approaches. The Athread approach enables us to achieve exceptional memory control and usage, efficient vectorization, and sophisticated utilization of the thread-level communication mechanism. We have also further refined the load-balance behaviors towards ultra-large-scale numerical simulation. By combining all these novelties, we achieved a simulation speed of 7.2 and 25.6 simulation-year-per-day (SYPD) for global 25-km and 100-km resolution, respectively (1.2- to 2.2-fold improvements over previous efforts), and a sustainable double-precision performance of 3.3 PFlops for a 750-m global simulation when using 10075000 cores.

Achieving an optimized mapping of Deep Learning (DL) operators to new hardware architectures is the key to building a scalable DL system. However, handcrafted optimization involves huge engineering efforts, due to the variety of DL operator implementations and complex programming skills. Targeting the innovative many-core processor SW26010 adopted by the 3rd fastest supercomputer Sunway TaihuLight, an end-to-end automated framework called swATOP is presented as a more practical solution for DL operator optimization. Arithmetic intensive DL operators are expressed into an auto-tuning-friendly form, which is based on tensorized primitives. By describing the algorithm of a DL operator using our domain specific language (DSL), swATOP is able to derive and produce an optimal implementation by separating hardware-dependent optimization and hardware-agnostic optimization. Hardware-dependent optimization is encapsulated in a set of tensorized primitives with sufficient utilization of the underlying hardware features. The hardware-agnostic optimization contains a scheduler, an intermediate representation (IR) optimizer, an auto-tuner, and a code generator. These modules cooperate to perform an automatic design space exploration, to apply a set of programming techniques, to discover a near-optimal solution, and to generate the executable code. Our experiments show that swATOP is able to bring significant performance improvement on DL operators in over 88% of cases, compared with the best-handcrafted optimization. Compared to a black-box autotuner, the tuning and code generation time can be reduced to minutes from days using swATOP.

The Community Atmosphere Model (CAM) is ported, redesigned, and scaled to the full system of the Sunway TaihuLight, and provides peta-scale climate modeling performance. We refactored and optimized the complete code using OpenACC directives at the first stage. A more aggressive and finer-grained redesign is then applied on the CAM, to achieve finer memory control and usage, more efficient vectorization and compute and communication overlapping. We further improve the CAM performance of a 260-core Sunway processor to the range of 28 to 184 Intel CPU cores, and achieve a sustainable double-precision performance of 3.3 PFlops for a 750 m global simulation when using 10,075,000 cores. CAM on Sunway achieves the simulation speed of 3.4 and 21.5 simulation-year-per-day (SYPD) for global 25-km and 100-km resolution respectively; and enables us to perform, to our knowledge, the first simulation of the complete lifecycle of hurricane Katrina, and achieve close-to-observation simulation results for both track and intensity.

This paper presents a novel method for estimating parameters of financial models with jump diffusions. It is a Particle Filter based Maximum Likelihood Estimation process, which uses particle streams to enable efficient evaluation of constraints and weights. We also provide a CPU-FPGA collaborative design for parameter estimation of Stochastic Volatility with Correlated and Contemporaneous Jumps model as a case study. The result is evaluated by comparing with a CPU and a cloud computing platform. We show 14 times speed up for the FPGA design compared with the CPU, and similar speedup but better convergence compared with an alternative parallelisation scheme using Techila Middleware on a multi-CPU environment.

American options are popularly traded in the financial market, so pricing those options becomes crucial in practice. In reality, many popular pricing models do not have analytical solutions. Hence techniques such as Monte Carlo are often used in practice. This paper presents a CPU-FPGA collaborative accelerator using state-of-the-art Least-Square Monte Carlo method, for pricing American options. We provide a new sequence of generating the Monte Carlo paths, and a precalculation strategy for the regression process. Our design is customisable for different pricing models, discretisation schemes, and regression functions. The Heston model is used as a case study for evaluating our strategy. Experimental results show that an FPGA-based solution could provide 22 to 64.5 times faster than a single-core CPU implementation.