CPU Fan not detecting in bios but spinning

[umairbasit]

I have had my pc for about an year and this morning when i turned it on, i received an error that the CPU FAN is not working, press F1.
So i went in to the bios and i noticed all other case fans are working and outputting RPMs. However, the CPU fan in not outputting anything it just says N/A..
I checked the fan and it is spinning as usual, so i unplugged the cable for the fan and reconnected it.. but no detection in the bios. Then, i unplugged the cable and plugged it into the connector right beside the Cpu fan that says CPU OPT FAN. And now it is being detected in the bios and i can see the RPMs, however it is spinning a little faster than before.
So my question is whether it is safe to have the CPU fan connected to CPU OPT Fan?
And also if anyone can shed some light on to why this happened to me suddenly or if there is a way to fix it..
Thank you

 

[Gam3r01]

The cpu opt slot is for an optional cpu fan, meaning if you have 2 fans or if the cable wont reach you can use that fan port. So yes it is perfectly safe and is spinning faster because it is adjusting to the cpus needs now.