ozzlo said:no there is no way to tell... all chips are different...
the only way to see how low your chip can go...
use centrino hardware control and in baby steps lower the cpu voltage... after each time you lower the voltage @800mhz run the Centrino Hardware Control stress test utility (it's basically prime 95 but instead it will run at the frequency+voltage that you set up and run it at full load) you can't test this with prime 95 because it will immediatelly jump to 1.7ghz @full load and you will have a different voltage for 1.7ghz
after you find the lowest stable voltage for 800mhz then you do the same thing for 1ghz and then again for 1.2ghz and 1.4ghz and 1.6ghz and finally 1.7ghz (numbers not exact because I don't have a 1.7ghz chip to reference which speeds centrino hardware control uses);
If I remember I can get you the table by maybe tomorrow... Which is kinda useful... it's like buried on pg 35 of the photo guide to pinmodding on the notebookforums in the dell section...
I'll give the CHC a try.