user41056: Is it safe to run an arduino pro mini 3.3v by 5v?
I mean directly connect 5v to vcc not raw pin.

user2881: Yes you can. 
The only difference between the 3.3 V and 5 V Pro Mini is the crystal and the voltage regulator. 

user42539: Yes, an 8 MHz resonator-clocked Promini will happily work at 5V vs 3.3V.
If you want, add a diode from VCC to the RAW pin to protect the regulator, altho it's datasheet does not indicate such is warranted.  Anecdotally, I used about 10 of these in my fencing club powered from 5V to the VCC line for quite a few years with no such protection and they ran fine for ~ 10 years, until we closed the club.

41056: <p>Is it safe to run an arduino pro mini 3.3v by 5v?
I mean directly connect 5v to vcc not raw pin.</p>
 2881: <p>Yes you can. </p>

<p>The only difference between the 3.3 V and 5 V Pro Mini is the crystal and the voltage regulator. </p>
 42539: <p>Yes, an 8 MHz resonator-clocked Promini will happily work at 5V vs 3.3V.</p>

<p>If you want, add a diode from VCC to the RAW pin to protect the regulator, altho it's <a href="http://ww1.microchip.com/downloads/en/DeviceDoc/20005785A.pdf" rel="nofollow noreferrer">datasheet</a> does not indicate such is warranted.  Anecdotally, I used about 10 of these in my fencing club powered from 5V to the VCC line for quite a few years with no such protection and they ran fine for ~ 10 years, until we closed the club.</p>
