Now I have these Arduino Pro Mini from Sparkfun. They are the latest version that I know (yeah, it's the one that have those horrible misaligned pins). Now they are designed around the ATmega328P and have a 16MHz crystal on them.
Now, my question is: Can I run an ATmega328 with a 16MHz crystal while supplying ONLY 3.3V.
The reason I'm doing this is because 5V / 16MHz Pro Minis from China are way cheaper then 3.3 / 8MHz.
Facts that I already know:
If I follow the datasheet to the the letter, this configuration should not work. BUT... After some test, it did work.
Also, I want an answers based on personal experience (NOT OPINIONS) and not datasheet and specs.
[EDIT] Including a way to use the internal clock (at 8MHz) of the ATmega328P would really help!