Why is Ubuntu Mate 16.04 runs hotter than Windows 7 on my Core2 and ATI Mobility Radeon 3xxx laptop?
Solution 1:
If your main concern is CPU/GPU heat control, you can install TLP:
sudo apt install tlp tlp-rdw
After installation run sudo tlp start
and reboot.
TLP provides AMD Radeon GPU power management (KMS and DPM), this is probably what you need.
You will see reduced heating after installation and reboot. However, it may take a few days to get the full effect of TLP.
TLP provides power management and longer battery life as well.
Please read more about TLP here.
Solution 2:
After almost 6 months since I asked, I finally found the answers.
I simply googled 'fglrx'. From there to : https://help.ubuntu.com/community/BinaryDriverHowto/AMD. Don't install the fglrx or any AMD proprietary driver. As the AMD proprietary drivers is only supported up to Linux kernel 3.4 (Go look it up at official AMD's driver download website.)
Go back up one-level to : https://help.ubuntu.com/community/BinaryDriverHowto/. Look it up and determine which driver you need / can use.
In my case, I found the fix inside the open source RadeonDriver link there : https://help.ubuntu.com/community/RadeonDriver, the simple fix is in the 'Power Management' section.
It says:
For the most recent ATI/AMD graphic cards supported by the Radeon driver, DPM (Dynamic Power Management) should work automatically without additional steps.
Instead if you notice overheating problems and/or you have an old Radeon HD graphic card, you can enable DPM by adding a boot parameter. This should greatly help power consumption, especially when idle. To do so, edit /etc/default/grub and add the 'radeon.dpm=1' to the GRUB_CMDLINE_LINUX_DEFAULT line, so it would look something like:
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash radeon.dpm=1"
After you save/quit the text editor, update grub:
sudo update-grub
It basically activates the Radeon driver DPM (Dynamic Power Management), a feature added in 2013 in the open-sourced Radeon driver (look up 'radeon dpm'), by modifying / adding the kernel boot parameter. The fix was easy enough and works for me. My VGA temp is now about 47-49 C when idle, on par with my idle temp using Windows 7.