# [solved] Fan problem ATI HD4770

## disi

I have an Asus Crosshair III Formula and Antec Titan 650 case that comes with 1 rear 120mm standard fan (TriCool 3-speed switch). 

This Fan works perfectly on Windows, but if I boot into Linux (gentoo-sources-2.6.30-r5) it spins up every few seconds (3-5). The sound is like when you start the computer and the fan goes to full speed for half a second.

It is not really a big deal, but totally annoys me. No system load, same happens on single user mode. What I need to know is where to start. I tested every combination of the BIOS Settings regarding case fans and cannot solve the problem. Same problem on the System Rescue CD as well. The CPU runs smoothly on 800MHz all the time...

I'll post more information later, when I am at home. Is this a problem with the kernel, the BIOS or the hardware?

My ideas are:

1. disconnect the case fan and check if the temperature looks fine

2. connect the fan somewhere else on the board

3. upgrade kernel?

Thanks for the answers.  :Smile: 

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## E001754

I connected my Antec solo's tricool directly to PSU.

Then, with the 3 speed switch, I set the fan speed the lowest speed. The fan continously runs at lower speed, noiseless.

There is no BIOS or Kernel in this story.

Couldn't you plug your tricool the same way, avoiding the motherboard plug ?

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## disi

Sorry, it is not the case fan, it is actual connected as you described to the PSU. I unplugged it and still the noise, so it must be the PSU fan.

Removing AC and FAN support from ACPI in the kernel doesn't change anything.

lm_sensors only detects the CPU fan, which goes constantly at around 2600 RPM

 :Question: 

//edit: could it be that the SSD has power peaks every few seconds that makes the PSU fan go faster? The Linux runs on the SSD, while Windows has a normal HD...

//edit: swapped some cables to the SSD and tested AHCI and IDE mode, no change   :Crying or Very sad: 

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## E001754

If you plug your fans on the motherboard, then the BIOS will control them.

ACPI is here to either take hand other the BIOS or to monitor what the BIOS is doing.

Depending on your fan, 2600 RPM can be noisy, but, anyway, finding which fan is noisy is always a tricky thing.

Try to unplug one after one, to see where the noise comes from, then it'll be easier to find out a solution of your noise annoyment...

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## disi

I think I got it... the PSU from Antec controls the fan speed via voltage used (looked that up)

Regarding this calculator: http://www.antec.outervision.com/PSUEngine

I would need 578w on 90% system load and 642w on 100% system load. 

The system has a 650w PSU.   :Embarassed: 

This evening I will try to get a 1000w or something and check if this solves the problem...

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## disi

New PSU "1000W iCute Modular ATX Quad VGA Power Supply" and same thing happens   :Mad:   I'll keep the PSU anyway...

No idea... could it be the fans on the graphic cards?

//edit: changed to x11-drivers/ati-drivers-9.9-r2 problem solved  :Smile: 

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## E001754

650 W PSU can't be overpowered even with strongly overclocked quadcore AND a strongly overclocked GPU.

Almost that you don't reach 100% system usage all the time, and, therefore, any PSU (quality PSU) can go beyond its max spec for a few seconds (there is hardly no reallife case in which you get 100% on CPU and GPU at the same time, except specific benchmarks).

The fan of my graphic card is very noisy when I start the computer, for about 3 seconds, then slows down (probably the time for the BIOS of the GFX card to initialize ?).

And the fan of my graphic card is very noisy when I play recent games, that put load on graphics. And my HD4870 can be VERY noisy when the fan reaches 100%

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## disi

Nice to know. It wasn't just that the fan was constantly noisy, but every few seconds made a noise... this seems to be gone with the new driver.

The new PSU is awesome, you can actually choose which cables you would like to plug into it. The old PSU had all the cables coming directly out of it as a whole bunch.   :Wink: 

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