The microarchitecture of Intel, AMD and VIA CPUs in pdf

The present manual describes the details of the microarchitectures of x86 microprocessors from Intel and AMD. The Itanium processor is not covered. The purpose of this manual is to enable assembly programmers and compiler makers to optimize software for a specific microprocessor. The main focus is on details that are relevant to calculations of how much time a piece of code takes to execute, such as the latencies of different execution units and the throughputs of various parts of the pipelines. Branch prediction algorithms are also covered in detail.

This manual will also be interesting to students of microarchitecture. But it must be noted that the technical descriptions are mostly based on my own research, which is limited to what is measurable. The descriptions of the "mechanics" of the pipelines are therefore limited to what can be measured by counting clock cycles or micro-operations (µops) and what can be deduced from these measurements. Mechanistic explanations in this manual should be regarded as a model which is useful for predicting microprocessor behavior. I have no way of knowing with certainty whether it is in accordance with the actual physical structure of the microprocessors. The main purpose of providing this information is to enable programmers and compiler makers to optimize their code.