Conneting fans to PSU rather than Mobo = more power consumption?

[Floydsound]

If I connect my case and CPU (Hyper 212 Evo) fans directly to the PSU rather than to the motherboard, will it consume more watts from the PSU?

System specs:
i5 2500k 3.3GHz stock
GTX 960 Gigabyte Windforce 2x
ASUS P8Z77-M
Antec Gamer 520W
4 case fans installed + 1 Hyper 212 Evo fan

Thanks in advance!

 

[Karsten75]

Of course it will not consume more power. All power on the motherboard is suplied by the PSU in any event.

However, you will have issues, since the motherboard will not be able to see a working CPU fan and will thus think your CPU fan is defective, impacting the processor.

Additionally, you will not be able to use temperature sensing and PWM fan control on the motherboard to adjust fan speed.

 

[Floydsound]

Of course it will not consume more power. All power on the motherboard is suplied by the PSU in any event.

However, you will have issues, since the motherboard will not be able to see a working CPU fan and will thus think your CPU fan is defective, impacting the processor.

Additionally, you will not be able to use temperature sensing and PWM fan control on the motherboard to adjust fan speed.

Thanks for the reply! My question came up after knowing that PSU connected fans run faster (and that's what I want in the end). How could I make the CPU fan run faster without connecting it directly to the PSU?

 

[scout_03]

what speed does the cpu fan report when you connect to the mobo cpu header .

 

[Floydsound]

what speed does the cpu fan report when you connect to the mobo cpu header .

Right now it's at 555 RPM on idle and about 660 RPM with a bit of gaming (while a case fan which is also connected to the motherboard is stable at about 820 RPM).

 

[Karsten75]

Different fans have different speeds. Without knowing what fans you have, it's hard to be very specific.

Additionally, some fans can be speed controlled - and there are two ways to control their speed. The "best" way is via PWM (pulse width modulation). These fans have 4 pins and one pin controls the speed. The other way is via voltage regulation. Many fan hubs and all 3-pin fans are controlled via voltage regulation.

The only reason a fan on the PSU will spin faster than the same fan on the motherboard is because the fan on the motherboard is speed controlled by either a fan controller, some special software or the BIOS of the motherboard. In all instances of controlled speed, one can safely assume it's because the components are not so hot that the controlling entity (software, BIOS or the person adjusting the fan controller) thinks it needs more aggressive airflow (and noise) to keep the components cooler.

You are seeing this "intelligent" speed control that's adjusted to the needs of the components if you see your CPU fan spinning at 555 and then at 660 "after a bit of gaming:

 

[Floydsound]

Different fans have different speeds. Without knowing what fans you have, it's hard to be very specific.

Additionally, some fans can be speed controlled - and there are two ways to control their speed. The "best" way is via PWM (pulse width modulation). These fans have 4 pins and one pin controls the speed. The other way is via voltage regulation. Many fan hubs and all 3-pin fans are controlled via voltage regulation.

The only reason a fan on the PSU will spin faster than the same fan on the motherboard is because the fan on the motherboard is speed controlled by either a fan controller, some special software or the BIOS of the motherboard. In all instances of controlled speed, one can safely assume it's because the components are not so hot that the controlling entity (software, BIOS or the person adjusting the fan controller) thinks it needs more aggressive airflow (and noise) to keep the components cooler.

You are seeing this "intelligent" speed control that's adjusted to the needs of the components if you see your CPU fan spinning at 555 and then at 660 "after a bit of gaming:

Thanks a lot, mate!

After some good 2 hours of Tomb Raider, the CPU fan reached a maximum of 949 RPM and the case fan reached 964 RPM.

I guess I don't have to be worried about this after all

CPU temps are 32ºC idle and 60ºC full load after hours of GTA V.

 

[scout_03]

mine run at 734 rpm and i have a cpu temp of 29 c then it look ok .