[data from a 1.53 GHz Athlon 1800+]

PERFCTR INIT: vendor 2, family 6, model 6, stepping 2, clock 1534121 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 166 cycles
PERFCTR INIT: rdtsc cost is 14.1 cycles (1070 total)
PERFCTR INIT: rdpmc cost is 13.9 cycles (1059 total)
PERFCTR INIT: rdmsr (counter) cost is 51.7 cycles (3481 total)
PERFCTR INIT: rdmsr (evntsel) cost is 52.7 cycles (3541 total)
PERFCTR INIT: wrmsr (counter) cost is 82.9 cycles (5472 total)
PERFCTR INIT: wrmsr (evntsel) cost is 231.6 cycles (14993 total)
PERFCTR INIT: read cr4 cost is 2.0 cycles (300 total)
PERFCTR INIT: write cr4 cost is 62.9 cycles (4196 total)
PERFCTR INIT: write LVTPC cost is 9.2 cycles (757 total)
PERFCTR INIT: sync_core cost is 73.7 cycles (4883 total)
perfctr: driver 2.7.14, cpu type AMD K7/K8 at 1534121 kHz