Next is your fan’s voltage – this will tell you what type of electrical outlet the fan should be plugged into.

The first is the fan’s amperage – this will dictate how much power the fan will use. There are a few things you’ll need to know. Now that you know what type of fan your computer has, you need to determine its speed. I have provided detail guide on how you can identify fan speed here. To do this, open up a Windows calculator and type in “fan speed” followed by the number for the type of fan (case, CPU or graphics card) that you want to control. Once you know which type of fan your computer has, you need to determine its speed. Case fans are found in computers with cases or power supplies CPU fans are used on desktops and laptops and graphics card fans cool down the video card. There are three types of fans: case fans, CPU fans, and graphics card fans. To control fan speed, you first need to determine what type of fan your computer has. However, if you don’t have enough air moving through your computer, it can get too hot and cause problems. It helps to move air in and out of the computer case, keeping it cool.

I recently built an ITX with specs does not match to the case, caused literally everything to overheat, and all other things are solved (CPU with a custom made cooler and GPU with super noiysy industrial case fan)but the PSU, the PSU causedd most problem, it's overheating shuts the system down while gaming, and that's bugging me alot since every time i play videogames, th system shuts down in the middle of the game, i just asked the forum if i could limit the PSU wattage to prevent overheating or not, and the answer is no.The case fan is one of the most important parts of the computer system. The other ppl asking this is to make th fan run slower, but i'm here cuz i feel like my PSU's fan is running too slow and here is the story:

Bios fan speed