# Graphics card gets MUCH hotter in ubuntu than windows



## grandson (Oct 23, 2005)

I've noticed that my laptop gets hotter much faster when I'm running Ubuntu, and thanks to ThinkWiki I found out it's my ATI X1400 card that's the hottest thing in my laptop. It's usual running temperature is 80 degrees celsius, but playing Youtube videos for any appreciable length of time can make it rise to 90 (!). Is this likely a bug with ATI's proprietary driver, or is Ubuntu using the card to accelerate things that Windows just doesn't, like window management? I don't have beryl or anything running.


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## lotuseclat79 (Sep 12, 2003)

Hi grandson,

How are you measuring temperature of just the video card in your laptop - i.e. what tool are you using? If you are not using a tool to measure the temperature and simply relying on information in ThinkWiki - can you provide a link to that information? Temperature sensors built into a computer can detect disk temperatures, system temperature and fan speeds - for example, for Windows there is the freeware tool SpeedFan which can even automatically adjust fan speeds. I've never heard of a temperature sensor applied to only a video card, although there may be one.

Have you checked the specs on the ATi card's running temperature range from the ATi website?

I presume your laptop is a Thinkpad (either Lenovo or IBM). For your laptop have you checked out any documentation from the supplier wrt operational specs on running temperature?

Is there a manual or guide to configure the ATi card? Or, perhaps you ran some downloaded software that reconfigured it?

Check out any operational information from ATi. It may just be the case that the card has an inboard mechanism to accelerate past a certain threshold that you never noticed with Windows.

Also, are you sure that any inboard fan is still operating? Perhaps a fan has failed.

Look for operational temperatures for the processor in your laptop on the Internet using Google. They are fairly well documented. It may just be that your processor is one that is known to run hot.

-- Tom


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## grandson (Oct 23, 2005)

Hi, thanks for helping; I'm using these instructions and noticed that the fourth result from "cat /proc/acpi/ibm/thermal" is always the highest, and that page indicated that the T60's fourth number represents the sensor next to the GPU. The fan definitely works fine; it can go to maximum speed (7) through its own connection to the thermal sensors or I can set it manually, but in Ubuntu even maximum speed can't keep up with the heat generated.

Is there a way to determine the processing load that's being delegated for the GPU to perform? I'm guessing the problem is directly Linux-related, since it never gets this hot doing the same things -- like watching Youtube -- on Windows XP. Could there be something Windows does, like limit that processing load as a form of temperature control, that Linux doesn't?

I have tried to navigate ATI's (AMD's) website, and it is near impossible to find anything technically useful and not marketing-useful, for me at least. I did find the specs thanks to Google, but they don't seem to mention temperatures. I searched Google several times but I can't find anything descriptive relating to the X1400's temperature. Some people on forums mention their temperature ranges, but all are much lower than the one I'm seeing.


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## lotuseclat79 (Sep 12, 2003)

Hi grandson,

Well, I am impressed with the documentation in ThinkWiki - looks like a great resource.

Looking at the data I wonder if the T60's (i.e. your laptop I suppose) heatsink is cooling for both the cpu and vpu like the X31?

Still, that would not account for the difference you are seeing between the use of WinXP and Linux - assuming that you have a controlled experiment where you look at the exact same videos in one OS as the other. Is that the case, or are they different from what you remember?

How many applications are you running when you look at the videos? I would close down everything else and run a minimal set of services and applications while looking at the videos in order to establish a benchmark from which to further understand what is going on. The more standard the set of processes you throw at each, the better you can compare apples to apples instead of apples to oranges.

One other thing, does the ATi card run the same or different drivers for Windows vs. Linux? Probably a different version of the same driver is my guess. Drivers are specific to hardware on one side of the interface, and unique to the OS on the other, so there could be driver implementation differences at the OS level that is affecting the GPU's temperature. One OS's HAL (hardware abstraction layer) is not the same as another OS's.

Your original intuition about acceleration in that case might be spot on.

That said, laptops are notoriously confined in space as opposed to a desktop with a full tower where the temperatures are sure to be different, but how much different I do not know.

Hmm, if only there were some GPU monitoring software to tell us what's going on inside the GPU when one OS is running the same video as the other OS - then we could begin to unravel this mystery. Even better would be to set up a rig under either VMWare or Xen and then run the videos virtually on each OS - to maintain better control over collecting the experiments data to compare.

Sorry I'm not being much help - just trying to theorize how I would go about finding out more about the conditions causing these temperature observations.

-- Tom


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