[data from a 900 MHz Pentium-III (Coppermine)]

PERFCTR INIT: vendor 0, family 6, model 8, stepping 10, clock 896283 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 199 cycles
PERFCTR INIT: rdtsc cost is 38.4 cycles (2658 total)
PERFCTR INIT: rdpmc cost is 35.9 cycles (2498 total)
PERFCTR INIT: rdmsr (counter) cost is 91.4 cycles (6050 total)
PERFCTR INIT: rdmsr (evntsel) cost is 72.8 cycles (4864 total)
PERFCTR INIT: wrmsr (counter) cost is 80.7 cycles (5367 total)
PERFCTR INIT: wrmsr (evntsel) cost is 76.0 cycles (5069 total)
PERFCTR INIT: read cr4 cost is 1.9 cycles (322 total)
PERFCTR INIT: write cr4 cost is 42.2 cycles (2903 total)
PERFCTR INIT: sync_core cost is 106.2 cycles (7002 total)
perfctr: driver 2.7.5, cpu type Intel P6 at 896283 kHz

PERFCTR INIT: vendor 0, family 6, model 8, stepping 6, clock 913495 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 89 cycles
PERFCTR INIT: rdtsc cost is 38.1 cycles (2533 total)
PERFCTR INIT: rdpmc cost is 34.6 cycles (2306 total)
PERFCTR INIT: rdmsr (counter) cost is 91.4 cycles (5939 total)
PERFCTR INIT: rdmsr (evntsel) cost is 72.8 cycles (4754 total)
PERFCTR INIT: wrmsr (counter) cost is 80.7 cycles (5257 total)
PERFCTR INIT: wrmsr (evntsel) cost is 76.1 cycles (4962 total)
PERFCTR INIT: read cr4 cost is 2.0 cycles (220 total)
PERFCTR INIT: write cr4 cost is 42.2 cycles (2792 total)
PERFCTR INIT: write LVTPC cost is 37.6 cycles (2496 total)
perfctr: driver 2.7.3, cpu type Intel P6 at 913495 kHz