[data from a 266Mhz Pentium II (Klamath)]

PERFCTR INIT: vendor 0, family 6, model 3, stepping 4, clock 266621 kHz
PERFCTR INIT: NITER == 64
PERFCTR INIT: loop overhead is 102 cycles
PERFCTR INIT: rdtsc cost is 33.2 cycles (2230 total)
PERFCTR INIT: rdpmc cost is 28.4 cycles (1924 total)
PERFCTR INIT: rdmsr (counter) cost is 81.2 cycles (5302 total)
PERFCTR INIT: rdmsr (evntsel) cost is 69.4 cycles (4545 total)
PERFCTR INIT: wrmsr (counter) cost is 82.3 cycles (5372 total)
PERFCTR INIT: wrmsr (evntsel) cost is 74.8 cycles (4890 total)
PERFCTR INIT: read cr4 cost is 1.7 cycles (217 total)
PERFCTR INIT: write cr4 cost is 39.0 cycles (2604 total)
perfctr: driver 2.3.3, cpu type Intel Pentium II at 266621 kHz