Cache Pollution - Increasing Importance

Increasing Importance

The reason why cache pollution control has been increasing in importance, is because the penalties caused by the so-called "memory wall" keep on growing. Chip manufacturers continue devising new tricks to overcome the ever increasing relative memory-to-CPU latency. They do that by increasing cache sizes and by providing useful ways for software engineers to control the way data arrives and stays at the CPU. Cache pollution control is one of the numerous devices available to the (mainly embedded) programmer. However, other methods, most of which are proprietary and highly hardware and application specific, are used as well.

Sometimes, however, even the most evolved and involved software is either insufficient or the very effort of software optimization crosses cost tolerance thresholds or profitability ratios as explained by the law of diminishing returns. In those cases the ball shifts back to the court of hardware engineers, and the "trick game" starts again. The relatively recent surge of interest in the system-on-a-chip concept (such as the Cell processor) is fueled by these issues.