Computer architecture

I recently attended the 45th ACM/IEEE International Symposium on Computer Architecture (ISCA) in Los Angeles, and was struck by the atmosphere of dramatic change in the field. First, a bit of perspective: For the last 15 years, computer architecture, and as a consequence computing as a whole, has been disrupted from below with the end of Dennard Scaling,1 producing a dramatic slowing in the growth of clock rate and single-thread performance, a shift to multicore, and the rise of throughput engines such GPUs. In addition, and in particular on mobile platforms, we have seen the rise of heavily customized architectures in mobile and embedded devices. These changes, precipitated by device and circuit-level effects, have rippled through the software stack compelling large-scale software rewrites, new compiler techniques and programming approaches, and the pervasive adoption of parallelism as a fundamental basis of performance. In the past three years, we have seen the effective end of Moore's Law scaling, with per transistor prices flat or increasing with recent technology nodes,2 and the slowing rate of advance to new process nodes at Intel (and across the industry).3