The objective of this research is to design a high-performance NAND flash memory system with a data buffer. The proposed buffer system in the NAND flash memory consists of two parts, i.e., a fully associative temporal buffer for temporal locality and a fully associative spatial buffer for spatial locality. We propose a new operating mechanism for reducing overhead of flash memory, that is, erase and write operations. According to our simulation results, the proposed buffer system can reduce the write and erase operations by about 73% and 79% for spec application respectively, compared with a fully associative buffer with two times more space. Futhermore, the average memory access time can improve by about 60% compared with other large buffer systems.

The multipass rendering method based on the global illumination model can generate the most photo-realistic images. However, since the multipass rendering method is very time consuming, it is impractical in the industrial world. This paper discusses a massively parallel processing approach to fast image synthesis by the multipass rendering method. Especially, we focus on the performance evaluation of the view-dependent object-space parallel processing on the (Mπ)2 which has been proposed in our previous paper. We also propose two kinds of distributed frame buffer system named cached frame buffer and multistage-interconnected frame buffer. These frame buffer systems can solve the access conflict problem on the frame buffer. The simulation results show that the (Mπ)2 has a scalable performance. For example, the (Mπ)2 with more than 4000 processing elements can achieve an efficiency of over 50%. We also show that both of the proposed distributed frame buffer systems can relieve the overhead due to frame buffer access in the (Mπ)2 in the case that a large number of high-performance processing elements are adopted in the system.

This paper proposes a hierarchical parallel processing system for the multipass rendering method. The multipass rendering method based on the integration of radiosity and ray-tracing can synthesize photo-realistic images. However, the method is also computationally expensive. To accelerate the multipass rendering method, the system, called (Mπ)2, employs two kinds of parallel processing schemes. As a coarse-grain parallel processing, object-space parallel processing with multiple processing elements based on the object-space subdivision is adapted, and each processing element (PE) is equipped with multiple pipelined units for a fine-grain parallel processing. To balance load among the system, static load balancing at the PE level and dynamic load balancing at the pipelined unit level within the PE are introduced. Especially, we propose a novel static load allocation scheme, skewed-distributed allocation, which can effectively distribute a three-dimensional object space to one- or two-dimensional processor configuration of the (Mπ)2 system. Simulation experiments show that the two-dimensional (Mπ)2 systems with the skewed-distributed allocation outperform the three-dimensional systems with the non-skewed distributed allocation. Since lower dimensional systems can be built at a lower cost than higher dimensional systems, the skewed-distributed allocation will be meritorious. Besides, by the combination of static load balancing by the skewed-distributed allocation and the dynamic load balancing by dynamic ray allocation within each PE, the system performance can be further boosted. We also propose a cached frame buffer system to relieve access collision on a frame buffer.