So i got the noctua d15 i had it for a while and they always ramped up at full rpm then slowed down to silence. i thought this was normal until i watched a build video yesterday (by hardwarekanucks) and his fans started up silently. Did i miss something when setting up my pc?
Do you have a PWM profile setup in BIOS?
yup. mobo is asus hero vii.
hmm strange I have noctua fans as well and mine are completely silent. Try checking if screws are tight (case fans) and check the CPU fans are secured to the heatsink. Only things I can think of
my rog impact does the same but im running coolermaster and f8 fans. usually they are off/on low. never really bothered me. still better than the old days hearing win 3.1/ 95 starting
I suppose mine would, if they weren't already x5 high speed fans running at slightly negative air pressure. My PC sounds like an outdoor AC unit.
My PC does it too, my old notebook also did it so I never once even considered that it's abnormal..
My mobo is a Z97 if this becomes relevant somehow.
It's a kind of precautionary measure. Some fans can't start spinning at lower voltages, so the PC will start up with all of the fan headers at 12V for a couple of seconds to get them going.
Some PC's I've built start up silently, some start up with a quick little "burst". Then there is my server, which ramps up its Delta fans for about 10 seconds before going silent, and there is my personal PC which has a fan controller that runs the fans at full speed for 20ish seconds for "dust removal". Its normal for PC's to do this(they ramp up the fan for diagnostic purposes and/or dust removal).
Like @Zavar said. Its just to make sure all fans are spinning. Ive had a couple laptops that will do that to get rid of dust.
all of my servers, and pc's start up like that. I know most of pc's don't but worry not about it - its a good thing.
I have an ASRock Extreme9 Z77 and that thing ramps the fans up partway until the OS loads, then it drops them down to low. Only thing that has ever made them go up other than that is ramping the CPU up to 5GHz and giving it loads of work.
It's a feature. You didn't miss anything. It's basically for diagnostics like said before, to make sure that they work and assurance that they actually start up.
The SuperIO on the motherboard of the build you watched is probably something new(er) and does things differently vs. your motherboards SuperIO.
Or did you actually mean this at 7:00?
That's a boot from sleep, not a cold boot. The SuperIO and etcetera is already initialized and iirc, when I was still using my motherboard (Gene-Z Z68) to control the fans it didn't do a full ramp up.
There's two reason your computer does this. The first one is to test the fans capacity to see if it's working, and to see what limits it's capable of. The second is to blow some excess dust out of whatever is behind it, i.e. a heatsink, radiator etc, steel mesh etc.