In November 1971, Intel introduced the world's first single-chip microprocessor, the Intel 4004. It had 2,300 transistors, ran at a clock speed of up to 740 KHz, and delivered 60,000 instructions per second while dissipating 0.5 watts. The following four decades witnessed exponential growth in compute power, a trend that has enabled applications as diverse as climate modeling, protein folding, and computing real-time ballistic trajectories of angry birds. Today's microprocessor chips employ billions of transistors, include multiple processor cores on a single silicon die, run at clock speeds measured in gigahertz, and deliver more than 4 million times the performance of the original 4004. Where did these incredible gains come from? This article sheds some light on this question by introducing CPU DB (cpudb.stanford.edu), an open and extensible database collected by Stanford's VLSI (very large-scale integration) Research Group over several generations of processors (and students). We gathered information on commercial processors from 17 manufacturers and placed it in CPU DB, which now contains data on 790 processors spanning the past 40 years. In addition, we provide a methodology to separate the effect of technology scaling from improvements on other frontiers (e.g., architecture and software), allowing the comparison of machines built in different technologies. To demonstrate the utility of this data and analysis, we use it to decompose processor improvements into contributions from the physical scaling of devices, and from improvements in microarchitecture, compiler, and software technologies. AN OPEN REPOSITORY OF PROCESSOR SPECS While information about current processors is easy to find, it is rarely arranged in a manner that is useful to the research community. For example, the data sheet may contain the processor's power, voltage, frequency, and cache size, but not the pipeline depth or the technology minimum feature size. Even then, these specifications often fail to tell the full story: a laptop processor operates over a range of frequencies and voltages, not just the 2 GHz shown on the box label. Not surprisingly, specification data gets harder to find the older the processor becomes, especially for those that are no longer made, or worse, whose manufacturers no longer exist. We have been collecting this type of data for three decades and are now releasing it in the form of an open repository of processor specifications. The goal of CPU DB is to aggregate detailed processor specifications into a convenient form and to encourage community participation, both to leverage this information and to keep it accurate and current. CPU DB (cpudb. stanford.edu) is populated with desktop, laptop, and server processors, for which we use SPEC 13 as our performance-measuring tool. In addition, the database contains limited data on embedded cores, for which we are using the CoreMark benchmark for performance. 5 With time and help from the community, we hope to extend the coverage of embedded processors in the database. ...
