ok, this is how you can tell... go to the bios or at boot up, look closely and it tell your the speed!!!!
the overclocked cpu they sell are only overclock ready, not overclocked. with the t-bird you only control the clock with your mobo.
If you can't beat 'em kill 'em
athlon "SLOTA" thunderbird 700@1050mhz
mpjesse is correct. you should go check the numbers. here is an example of what you will see on the top of the black casing of your Athlon. It would be something like <font color=blue><b>AMDK7850MPR52B A</b></font color=blue>. What does this mean?
The most important part here is the reserved character.It could be either "A" or "C". If it is "C", it is an older 0.25 micron CPU. If it is "A", you may hope for some serious OCing coz you have a newer 0.18 micron CPU.
In your question on determining the speed, in our example, the speed is 850MHz.
Btw, I got this info from <A HREF="http://www.aceshardware.com" target="_new">http://www.aceshardware.com</A>