Windows 2000 Performance Guide

Pentium Pro Hardware Counters

The measurement facility in the Intel P6 or Pentium Pro processors (including Pentium II, III, and IV) was strengthened to help hardware designers cope with the demands of more complicated multiprocessor designs. By installing the CPUmon freeware utility available for download at http://www.sysinternals.com, system administrators and performance analysts can access these hardware measurements. While the use of these counters presumes a thorough understanding of Intel multiprocessing hardware, we hope that the previous discussion of multiprocessor design and performance has given you the confidence to start using them to diagnose specific performance problems associated with large-scale Windows 2000 multiprocessors. The P6 counters provide valuable insight into multiprocessor performance, including direct measurement of the processor instruction rate, Level 2 cache, TLB, branch prediction, and the all-important shared-memory bus.

CPUmon, a freeware Pentium counter utility, lets you enable and then disable the Pentium counters for a specific interval, as illustrated in Figure 5-11. The CPUmon user interface, which separates the various counters that are available into different classes, is user-friendly. (CPUmon assigns the counters different names from the ones the x86 Perf Meter application does, which is confusing. Even more confusing, some of the available P6 counters are missing entirely from the program.) Once the Pentium counters you select ...