심재웅 교수

Current-generation Deep Neural Networks (DNNs), such as AlexNet and VGG, rely heavily on dense floating-point matrix multiplication (GEMM), which maps well to GPUs (regular parallelism, high TFLOP/s). Because of this, GPUs are widely used for accelerating DNNs. Current FPGAs offer superior energy efficiency (Ops/Watt), but they do not offer the performance of today's GPUs on DNNs. In this paper, we look at upcoming FPGA technology advances, the rapid pace of innovation in DNN algorithms, and con

Deep neural networks (DNNs) are widely used in data analytics, since they deliver state-of-the-art accuracies. Binarized neural networks (BNNs) are recently proposed optimized variant of DNNs. BNNs constraint network weight and/or neuron value to either +1 or −1, which is representable in 1 bit. This leads to dramatic algorithm efficiency improvement, due to reduction in the memory and computational demands. This paper evaluates the opportunity to further improve the execution efficiency of BNNs

With the emergence of data science, graph computing has become increasingly important these days. Unfortunately, graph computing typically suffers from poor performance when mapped to modern computing systems because of the overhead of executing atomic operations and inefficient utilization of the memory subsystem. Meanwhile, emerging technologies, such as Hybrid Memory Cube (HMC), enable the processing-in-memory (PIM) functionality with offloading operations at an instruction level. Instruction

Tuning code for GPGPU and other emerging many-core platforms is a challenge because few models or tools can precisely pinpoint the root cause of performance bottlenecks. In this paper, we present a performance analysis framework that can help shed light on such bottlenecks for GPGPU applications. Although a handful of GPGPU profiling tools exist, most of the traditional tools, unfortunately, simply provide programmers with a variety of measurements and metrics obtained by running applications, a

Recurrent neural networks (RNNs) provide state-of-the-art accuracy for performing analytics on datasets with sequence (e.g., language model). This paper studied a state-of-the-art RNN variant, Gated Recurrent Unit (GRU). We first proposed memoization optimization to avoid 3 out of the 6 dense matrix vector multiplications (SGEMVs) that are the majority of the computation in GRU. Then, we study the opportunities to accelerate the remaining SGEMVs using FPGAs, in comparison to 14-nm ASIC, GPU, and

Recent technology advancements allow for the integration of large memory structures on-die or as a die-stacked DRAM. Such structures provide higher bandwidth and faster access time than off-chip memory. Prior work has investigated using the large integrated memory as a cache, or using it as part of a heterogeneous memory system under management of the OS. Using this memory as a cache would waste a large fraction of total memory space, especially for the systems where stacked memory could be as l

Die-stacking technology allows conventional DRAM to be integrated with processors. While numerous opportunities to make use of such stacked DRAM exist, one promising way is to use it as a large cache. Although previous studies show that DRAM caches can deliver performance benefits, there remain inefficiencies as well as significant hardware costs for auxiliary structures. This paper presents two innovations that exploit the bursty nature of memory requests to streamline the DRAM cache. The first

General Matrix to Matrix multiplication (GEMM) is the cornerstone for a wide gamut of applications in high performance computing (HPC), scientific computing (SC) and more recently, deep learning. In this work, we present a customizable matrix multiplication framework for the Intel HARPv2 CPU+FPGA platform that includes support for both traditional single precision floating point and reduced precision workloads. Our framework supports arbitrary size GEMMs and consists of two parts: (1) a simple a

While unified virtual memory and demand paging in modern GPUs provide convenient abstractions to programmers for working with large-scale applications, they come at a significant performance cost. We provide the first comprehensive analysis of major inefficiencies that arise in page fault handling mechanisms employed in modern GPUs. To amortize the high costs in fault handling, the GPU runtime processes a large number of GPU page faults together. We observe that this batched processing of page f

Convolutional neural networks (CNNs) are deployed in a wide range of image recognition, scene segmentation and object detection applications. Achieving state of the art accuracy in CNNs often results in large models and complex topologies that require significant compute resources to complete in a timely manner. Binarised neural networks (BNNs) have been proposed as an optimised variant of CNNs, which constrain the weights and activations to +1 or -1 and thus offer compact models and lower compu

This paper presents GSCore, a hardware acceleration unit that efficiently executes the rendering pipeline of 3D Gaussian Splatting with algorithmic optimizations. GSCore builds on the observations from an in-depth analysis of Gaussian-based radiance field rendering to enhance computational efficiency and bring the technique to wide adoption. In doing so, we present several optimization techniques, Gaussian shape-aware intersection test, hierarchical sorting, and subtile skipping, all of which ar

Interactive intelligent services, such as smart web search, are important datacenter workloads. They rely on dataintensive deep learning (DL) algorithms with strict latency constraints and thus require balancing both data movement and compute capabilities. As such, a persistent approach that keeps the entire DL model on-chip is becoming the new norm for realtime services to avoid the expensive off-chip memory accesses. This approach is adopted in Microsoft's Brainwave and is also provided by Nvi

Parallel machine learning workloads have become prevalent in numerous application domains. Many of these workloads are iterative convergent, allowing different threads to compute in an asynchronous manner, relaxing certain read-after-write data dependencies to use stale values. While considerable effort has been devoted to reducing the communication latency between nodes by utilizing asynchronous parallelism, inefficient utilization of relaxed consistency models within a single node have caused

This paper presents NeuRex, an accelerator architecture that efficiently performs the modern neural rendering pipeline with an algorithmic enhancement and supporting hardware. NeuRex leverages the insights from an in-depth analysis of the state-of-the-art neural scene representation to make the multi-resolution hash encoding, which is the key operational primitive in modern neural renderings, more hardware-friendly and features a specialized hash encoding engine that enables us to effectively pe

Die-stacked DRAM can provide large amounts of in-package, high-bandwidth cache storage. For server and high-performance computing markets, however, such DRAM caches must also provide sufficient support for reliability and fault tolerance. While conventional off-chip memory provides ECC support by adding one or more extra chips, this may not be practical in a 3D stack. In this paper, we present a DRAM cache organization that uses error-correcting codes (ECCs), strong checksums (CRCs), and dirty d