CPU opt fan speed showing as N/a in BIOS ?

[Lejend]

Hello everyone, I have an fx 8350 on an asus 990 fx R2.0

Was just wondering why in the BIOS it says that CPU opt fan as N/A.

Any help will be much appreciated ! :/

 

[Swordkd]

Probably because there isn't anything connected to that fan header?