Asrock Z77 Extreme 4 - Max Power for Fan Header ?

[argz]

Hi,

I need to know what is the max power for each fan header on the motherboard Asrock z77 Extreme 4 ? and the max power for all fan header ?

I want use 2 fans on 1 header (Delta afc1212de-pwm 120mm 1.60A + Thermaltake TT-1225 0.30A) =1.90A

Thanks.

[parsec]

Re: Asrock Z77 Extreme 4 - Max Power for Fan Header ?

The unwritten standard for mobo fan headers is 1 Amp, or 12W at 12V. You can't "borrow" power from one header to be used on another, the circuitry is not that strong and not designed to channel all the potential fan header power into one header. Your total of 1.90A is almost twice what a single header can handle, and would likely damage the board.

The power ratings for fans is rarely accurate, given tests I've seen. Some fans use less than their spec, others much more. IF you could find a test of your fans and verify they use less power than their rating, you might be Ok, might being the keyword.

You should consider a separate, add on fan controller if you need to use high power draw fans.

[raymondjpg]

Re: Asrock Z77 Extreme 4 - Max Power for Fan Header ?

Not wanting to hijack this thread, but I have two Noctua 120mm PWM fans running off the Chassis 1 (PWM) fan header on a Asrock X79 Extreme4. The reason being that I was looking to have both fans linked to CPU temperature control.

As it is I generally run the fans at a constant speed of around 770 rpm, or about 50% of maximum capacity.

The power rating for these fans from the Noctua site is Max. Input Power 0,6 W and Max. Input Current 0,05 A at 12V. Is that right? These figures are an order of magnitude less than those quoted for the Delta and Thermaltake in the original post.

Even assuming that the figures for the Noctua should be multiplied by 10, am I right in thinking

1. that at max power and current these two fans connected to the one header would fall into specs for the fan header, and

2. even if the power rating for the fans is understated that running them at half speed would be very unlikely to overload the header?

[parsec]

Re: Asrock Z77 Extreme 4 - Max Power for Fan Header ?

Your Noctua fans are well within the power limits of your fan header, even when used in pairs, given the specs. The only Noctua fan test I know of (and trust) is of a 140mm model, rated at 0.1A, and at full speed actually used 1.32W, a bit over the rated current, but nothing to complain about. But we can assume the specs for your fans are correct, given the test of the 140mm fan. One fan header on your board can provide 12 Watts, so you are fine.

Other ASRock boards have two CPU fan headers, that are supposed to be synchronized, even though the other one is a three pin header, at least on some boards. In theory, you could use one fan on each CPU fan header, and discover if they are truly synchronized.

The Delta fan in the original post is a high RPM, high CFM, and loud fan, rated at 1.6A, or using 19.2 Watts. That is a higher power usage than some HDDs. It would either overload the fan header and possibly ruin it, or if the header was current limited safely, never run at it's highest speed. Many separate fan controllers could not handle that fan, they would need to be 25 Watts per channel to be safe.

Most fans use much less power than that Delta does, but the Delta is an extremely high CFM fan. Fan manufacture know they should keep the power use of their products at 1A or less, for use with mother boards.

For a real look at how fans operate, check this review, and other fan reviews here:

140 mm Fan Roundup - X-bit labs

[raymondjpg]

Re: Asrock Z77 Extreme 4 - Max Power for Fan Header ?

That is reassuring, thank you.

My two CPU PWM fan headers are synchronised, CPU 1 running a radiator fan and CPU 2 an impeller in a liquid cooling system. The Chassis 1 PWM fan header that the two Noctua case fans are connected to is said to be linked to the CPU fan sensors on auto setting, but as I said I normally run them on manual at about 50% max speed. There is a second chassis fan header that is not linked to the CPU fan sensors, and could just as well be used for one or both Noctuas on manual settings.

All looks good the way things are, I think.