[data from a 1.5 GHz Pentium M]

PERFCTR INIT: vendor 0, family 6, model 13, stepping 6, clock 1496565 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 263 cycles
PERFCTR INIT: rdtsc cost is 45.7 cycles (3191 total)
PERFCTR INIT: rdpmc cost is 44.1 cycles (3089 total)
PERFCTR INIT: rdmsr (counter) cost is 104.4 cycles (6946 total)
PERFCTR INIT: rdmsr (evntsel) cost is 87.9 cycles (5893 total)
PERFCTR INIT: wrmsr (counter) cost is 154.7 cycles (10165 total)
PERFCTR INIT: wrmsr (evntsel) cost is 143.2 cycles (9429 total)
PERFCTR INIT: read cr4 cost is 3.0 cycles (459 total)
PERFCTR INIT: write cr4 cost is 52.8 cycles (3648 total)
PERFCTR INIT: write LVTPC cost is 8.8 cycles (827 total)
PERFCTR INIT: sync_core cost is 148.5 cycles (9768 total)
perfctr: driver 2.7.5, cpu type Intel P6 at 1496565 kHz

PERFCTR INIT: vendor 0, family 6, model 9, stepping 5, clock 1495323 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 282 cycles
PERFCTR INIT: rdtsc cost is 48.2 cycles (3368 total)
PERFCTR INIT: rdpmc cost is 44.8 cycles (3155 total)
PERFCTR INIT: rdmsr (counter) cost is 95.0 cycles (6366 total)
PERFCTR INIT: rdmsr (evntsel) cost is 80.7 cycles (5448 total)
PERFCTR INIT: wrmsr (counter) cost is 143.4 cycles (9462 total)
PERFCTR INIT: wrmsr (evntsel) cost is 132.0 cycles (8733 total)
PERFCTR INIT: read cr4 cost is 2.5 cycles (444 total)
PERFCTR INIT: write cr4 cost is 49.5 cycles (3453 total)
PERFCTR INIT: write LVTPC cost is 8.7 cycles (842 total)
PERFCTR INIT: sync_core cost is 140.7 cycles (9291 total)
perfctr: driver 2.7.4, cpu type Intel P6 at 1495323 kHz