ATI 4800 Series Fan Control

[+shift. MVC]

For those of you having cooling problems with the ATI 4800 series with regards to not being able to change fan speed in the ATI Catalyst drivers I found a solution in another forum and I thought I'd share. This should lower your card's idle/load temperatures by quite a bit.

The original thread was for the ATI HD 4870, but I believe it should work as well for the 4850.

Use caution when performing this fix, and I am NOT responsible for any inherent problems that occur after applying this.

I'd love to take credit for this, but someone else came up with it. I wouldn't be surprised if the person worked for ATI either as it was his first post. Anyway, I'll cut to the chase. All you need to do is change just two values in the XML which is attached to an ATI Profile you created. I tried this and it worked perfectly, other than the noise generated by 65% fan speed as suggested. I'll experiment later. But it works and easy as anything. I edited his instructions just a hair. See below ....

http://forums.guru3d.com/showpost.ph...69&postcount=8

Make a profile in the CCC after turning on Overdrive and make sure clock and memory settings are correct.

For Vista

Then go to the following location and open the following file for editing "C:\Users\Your Windows ID\AppData\Local\ATI\ACE\Your CCC Profile.XML. The xml file will have the same name as the Catalyst Profile you saved. right click and hit edit.

For XP - Thanks Spartan for the path...

Then go to the following location and open the following file for editing "C:\Documents and Settings\Your Windows ID\Local Settings\Application Data\ATI\ACE\Your CCC Profile.XML. The xml file will have the same name as the Catalyst Profile you saved. right click and hit edit.

Now go down the page until you see the following lines in the XML file ...

<Feature name="FanSpeedAlgorithm_0">

<Property name="FanSpeedAlgorithm" value="Automatic" />

</Feature>

<Feature name="FanSpeedRPMTarget_0">

<Property name="Want" value="0" />

</Feature>

<Feature name="FanSpeedPercentTarget_0">

<Property name="Want" value="23" />

Change the "Property name="FanSpeedAlgorithm" value=" from "Automatic" to "Manual"

Then change "Property name="Want" value=" from "23" to your desired fan speed.

Save the file, then reload the Profile you just edited in the CCC. Done.

Edit 1:

After experimenting with my HIS HD4870 I found a fan-speed of 37% works best for me. My temps went from 79C at idle to 48C.

Edit 2:

Contrary to instrcutions posted on Guru3D by Bretware, most people are able to set their fan speed to "Automatic" rather than "Manual". Having it set to "Automatic" should allow the fan speed to ramp-up if needed beyond the fan-speed you entered. This doesn't work for me however and I must use "Manual".

I found the above in a thread by honestjohn @ HardForum.com - http://hardforum.com/showthread.php?t=1320351

Someone tell me if this works or not. It might save a lot of you the trouble of having to buy an aftermarket cooler, and for those of you whom I recommended an aftermarket cooler, I apologize.

Edited July 9, 2008 by -SHiFT-

[obiwong]

it works

haven't had any problems since i applied that change last week

[prz]

amazing tweak, using this on an older ati card (2600xt hd 512mb vram)

any cons to running the fan at 100 other than noise? (the fan on this card is so tiny i dont even notice with the other fans running)

[seethru]

I applied it but then reverted back. The card, while under Automatic control, barely goes above 87 Celsius. These were made to withstand high temperatures.

[Digitalx]

a friend just done it on 4850 and got 49?c idle with fan value set at 40. it is a gigabyte 4850.

[+shift. MVC]

There should be no problems with running the fan at 100% other than the noise.

[theyarecomingforyou]

Cheers. My card used to run at 89C under load but upping the speed from 32% to 40% dropped that to 77C, though with a slight increase in noise (acceptable because I'm overclocking and want to protect my card). For comedy value I upped it to 100% and it was like a vacuum cleaner.

[+shift. MVC]

Well any reference video card fan would be a vacuum cleaner at 100% :laugh:

[alavo03]

Other fan control method, but a hardware one:

http://professionalsat.blogspot.com/2008/0...ati-hd4850.html

Regards.

Carlos.

[Dashel]

Preface, 70-90C is the NORMAL, supported operating range for the 48xx series cards. Thermal failure occurs around 125C before which the fan would normally ramp up to 100% between 90-105C so it should never be an issue. Also contrary to conventional wisdom, there are little overclocking gains to be had by lowering temps.