6.5. Main Memory Performance Issues

Usually, not all data can be stored in the processor's caches. Some cache misses are inevitable for large applications. Therefore, the performance of a system's memory subsystem is the next area that can impact an application's performance. Both physical and virtual memory issues can cause problems.

6.5.1. Physical Memory

The amount of physical main memory available on a particular system depends on four criteria:

  • The number of physical slots available for memory boards

  • The density of RAM chips used to build the memory boards

  • The number of bits used to address physical memory

  • The amount of memory supported by the operating system

Today's HP systems may support anywhere from 128 MB to 512 GB of main memory. System ...

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