[data from a 1.0 GHz Athlon]

PERFCTR INIT: vendor 2, family 6, model 6, stepping 2, clock 1050288 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 159 cycles
PERFCTR INIT: rdtsc cost is 13.5 cycles (1025 total)
PERFCTR INIT: rdpmc cost is 13.3 cycles (1016 total)
PERFCTR INIT: rdmsr (counter) cost is 51.7 cycles (3474 total)
PERFCTR INIT: rdmsr (evntsel) cost is 52.7 cycles (3538 total)
PERFCTR INIT: wrmsr (counter) cost is 82.5 cycles (5441 total)
PERFCTR INIT: wrmsr (evntsel) cost is 231.4 cycles (14973 total)
PERFCTR INIT: read cr4 cost is 2.1 cycles (294 total)
PERFCTR INIT: write cr4 cost is 62.8 cycles (4181 total)
PERFCTR INIT: sync_core cost is 76.3 cycles (5047 total)
perfctr: driver 2.6.11, cpu type AMD K7/K8 at 1050288 kHz

PERFCTR INIT: vendor 2, family 6, model 4
PERFCTR INIT: NITER == 64
PERFCTR INIT: rdpmc ticks == 1679
PERFCTR INIT: rdmsr (counter) ticks == 3399
PERFCTR INIT: rdmsr (evntsel) ticks == 3453
PERFCTR INIT: wrmsr (counter) ticks == 5893
PERFCTR INIT: wrmsr (evntsel) ticks == 14955
PERFCTR INIT: read %cr4 ticks == 219
PERFCTR INIT: write %cr4 ticks == 4129
PERFCTR INIT: loop overhead ticks == 83
PERFCTR INIT: Athlon test0 == 0 (ok)
PERFCTR INIT: Athlon test1 == 35 (ok)
PERFCTR INIT: Athlon test2 == 35 (EvntSel0 does not override)
PERFCTR INIT: Athlon test3 == 0 (ok)