Hey, that's weird! I just tried your code again to see what CPU it says I have:

I tried it twice and I got this the first time:
x86 Family 6 Model 14 Stepping 8
Speed: 1596 Mhz
x86 Family 6 Model 14 Stepping 8
Speed: 1595 Mhz

But this again the second time:
x86 Family 6 Model 14 Stepping 8
Speed: 798 Mhz
x86 Family 6 Model 14 Stepping 8
Speed: 797 Mhz

Is there a way to make it constant?