[data from a 450MHz Pentium III (Katmai)]

PERFCTR INIT: vendor 0, family 6, model 7, stepping 3, clock 451026 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 89 cycles
PERFCTR INIT: rdtsc cost is 31.0 cycles (2078 total)
PERFCTR INIT: rdpmc cost is 34.3 cycles (2289 total)
PERFCTR INIT: rdmsr (counter) cost is 81.0 cycles (5279 total)
PERFCTR INIT: rdmsr (evntsel) cost is 68.9 cycles (4499 total)
PERFCTR INIT: wrmsr (counter) cost is 114.7 cycles (7433 total)
PERFCTR INIT: wrmsr (evntsel) cost is 105.3 cycles (6829 total)
PERFCTR INIT: read cr4 cost is 1.9 cycles (216 total)
PERFCTR INIT: write cr4 cost is 42.2 cycles (2794 total)
perfctr: driver 2.3.3, cpu type Intel Pentium III at 451026 kHz

PERFCTR INIT: vendor 0, family 6, model 7, stepping 3, clock 447872 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 90 cycles
PERFCTR INIT: rdtsc cost is 34.0 cycles (2271 total)
PERFCTR INIT: rdpmc cost is 34.8 cycles (2319 total)
PERFCTR INIT: rdmsr (counter) cost is 80.4 cycles (5239 total)
PERFCTR INIT: rdmsr (evntsel) cost is 68.9 cycles (4502 total)
PERFCTR INIT: wrmsr (counter) cost is 114.7 cycles (7435 total)
PERFCTR INIT: wrmsr (evntsel) cost is 105.1 cycles (6818 total)
PERFCTR INIT: read cr4 cost is 1.9 cycles (214 total)
PERFCTR INIT: write cr4 cost is 42.2 cycles (2795 total)
PERFCTR INIT: write LVTPC cost is 26.7 cycles (1802 total)
perfctr: driver 2.7.3, cpu type Intel P6 at 447872 kHz