Adjusting system fan speeds outside the bios?

[SUPER_MOOSE93]

I currently have two 120mm intake fans directly in front of my GPU; I removed the original GPU fans and fixed the Arctic 120mm fans to the bottom of the case so they were right up against the heat sink. I also have two 120mm exhaust fans at the top of the case. All 4 of these fans are run through the system fan header on the motherboard.

 

When I'm playing a game I crank these fans to 100%, I get great temps and the noise is basically none existent over the sound of the game itself. I would like to be able to drop the fan speed when I'm not running any games, just to cut the noise level and save the fans from an early death.

 

Is there a way to change system fan speeds without restarting the PC and entering the bios? maybe through software? 

 

I'm trying to avoid a fan controller because my case is packed already,  and I don't think it would fit 

[TrigrH]

You can create a fan curve that gives you these results as gaming will create higher load on temps.

 

For some reason if you don't want to do that:

Speedfan (free)

Argus Monitor (Paid)

[aDoomGuy]

Speedfan is no longer maintained meaning modern systems most often wont work. However a user on this forum made something that does work. Also he is really helpful too.