[data from a 1.6 GHz Pentium-M]

PERFCTR INIT: vendor 0, family 6, model 9, stepping 5, clock 1599024 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 278 cycles
PERFCTR INIT: rdtsc cost is 56.8 cycles (3917 total)
PERFCTR INIT: rdpmc cost is 43.9 cycles (3092 total)
PERFCTR INIT: rdmsr (counter) cost is 95.0 cycles (6359 total)
PERFCTR INIT: rdmsr (evntsel) cost is 80.7 cycles (5448 total)
PERFCTR INIT: wrmsr (counter) cost is 143.3 cycles (9455 total)
PERFCTR INIT: wrmsr (evntsel) cost is 132.0 cycles (8731 total)
PERFCTR INIT: read cr4 cost is 2.8 cycles (460 total)
PERFCTR INIT: write cr4 cost is 49.5 cycles (3451 total)
PERFCTR INIT: write LVTPC cost is 8.1 cycles (798 total)
PERFCTR INIT: sync_core cost is 140.7 cycles (9287 total)
perfctr: driver 2.7.5, cpu type Intel P6 at 1599024 kHz