[data from a 1.33 GHz Athlon XP 1500+]

PERFCTR INIT: vendor 2, family 6, model 6, stepping 2, clock 1343234 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 169 cycles
PERFCTR INIT: rdtsc cost is 13.3 cycles (1021 total)
PERFCTR INIT: rdpmc cost is 13.3 cycles (1026 total)
PERFCTR INIT: rdmsr (counter) cost is 51.9 cycles (3492 total)
PERFCTR INIT: rdmsr (evntsel) cost is 53.0 cycles (3564 total)
PERFCTR INIT: wrmsr (counter) cost is 79.9 cycles (5284 total)
PERFCTR INIT: wrmsr (evntsel) cost is 231.6 cycles (14997 total)
PERFCTR INIT: read cr4 cost is 2.2 cycles (313 total)
PERFCTR INIT: write cr4 cost is 63.0 cycles (4205 total)
PERFCTR INIT: write LVTPC cost is 10.3 cycles (830 total)
PERFCTR INIT: sync_core cost is 73.6 cycles (4883 total)
perfctr: driver 2.7.5, cpu type AMD K7/K8 at 1343234 kHz