Advances in IC processing allow for more microprocessor design options. The increasing gate density and cost of wires in advanced integrated circuit technologies require that we look for new ways to use their capabilities effectively. This paper shows that in advanced technologies it is possible to implement a single-chip multiproces-sor in the same area as a wide issue superscalar processor. We find that for applications with little parallelism the performance of the two microarchitectures is comparable. For applications with large amounts of parallelism at both the fine and coarse grained levels, the multiprocessor microarchitectnre outperforms the superscrdar architecture by a significant margin. Single-chip multiprocessor architectures have the advantage in that they offer localized imple-mentation of a high-clock rate processor for inherently sequential applications and low latency interprocessor communication for par-allel applications. 1

The circuit techniques used to implement a 600MHz, out-of-order, superscalar RISC Alpha microprocessor are described. Innovative logic and circuit design created a chip that attains 30+ SpecInt95 and 50+ SpecFP95, and supports a secondary cache bandwidth of 6.4GB/s. Microarchitectural techniques were used to optimize latencies and cycle time, while a variety of static and dynamic design methods balanced critical path delays against power consumption. The chip relies heavily on full custom design and layout to meet speed and area goals. An extensive CAD suite guaranteed the integrity of the design. 1.

Advances in IC processing allow for more microprocessor design options. The increasing gate density and cost of wires in advanced integrated circuit technologies require that we look for new ways to use their capabilities effectively. This paper shows that in advanced technologies it is possible to implement a single-chip multiprocessor in the same area as a wide issue superscalar processor. We find that for applications with little parallelism the performance of the two microarchitectures is comparable. For applications with large amounts of parallelism at both the fine and coarse grained levels, the multiprocessor microarchitecture outperforms the superscalar architecture by a significant margin. Single-chip multiprocessor architectures have the advantage in that they offer localized implementation of a high-clock rate processor for inherently sequential applications and low latency interprocessor communication for parallel applications. 1