What is a CPU counter?

CPU Counters

CPU counters are a feature of the computer's CPU that store the count of hardware-related events. The Visual Studio 2008 Profiler enables you to use these event counts as the sampling interval or collect the event counts when you profile using instrumentation. Performance counters are CPU-specific. Different models and versions of a CPU can have significantly different configuration settings to enable the same performance counter. Visual Studio 2008 Profiler portable events decouple some of the common performance counters from specific processors and enable you to collect or sample generic performance events. If you want to count a particular event when profiling, for example, L2 cache misses, the user can build a performance session around that event source. You can do this on any CPU with L2 cache. The performance session can be moved from platform to platform without modification. The Visual Studio 2008 profiler continues to support particular events for a specific platform. For example, a developer on a Pentium 4 platform might want to count events that are specific to the NetBurst architecture. This event is not portable, but still available to the developer for a specific performance session on a specific platform.