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zaffy

Member

Registered: 2013-12-08

Posts: 12

[SOLVED] Powering off discrete GPU powers down my fan

I have lenovo thinkpad edge e520 and I am experiencing an awful issue.

When I pwoer down my discrete graphics using vgaswitcheroo (often at boot), my fan stops working. When I power on the gpu using /sys/kernel/debug/vgaswitcheroo/switch, the fan starts to work again. Any ideas why is this happening ? I also tried to turn off my gpu with turn_off_gpu.sh but all methods failed. The graphics is amd radeon hd 6630M.

Any help would be much appreciated.

EDIT: I figured out how to power it down with turn_off_gpu (found corrent code), but the behavior is still the same :/
Also when the fan is cooling and I turn off the gpu the fan is cooling until the system is rebooted.

Last edited by zaffy (2013-12-13 17:36:36)

zaffy

Member

Registered: 2013-12-08

Posts: 12

Re: [SOLVED] Powering off discrete GPU powers down my fan

SOLVED!

It turned out that the problem was recently flashed bios, which probably turned off thermal sensor with discrete graphics as well. So I dowloaded the first lowest bios version I found on lenovo support site and flashed bios with it. Now everything works with vgaswitcheroo, but I had some troubles with turn_off_gpu.sh so I now use just vgaswitcheroo.

pragma

Member

Registered: 2013-12-30

Posts: 1

Re: [SOLVED] Powering off discrete GPU powers down my fan

Hi, what version of the bios did you downloaded ?

zaffy

Member

Registered: 2013-12-08

Posts: 12

Re: [SOLVED] Powering off discrete GPU powers down my fan

Hi,  I don't really exactly which version to be honest but I think, the first one (not latest one).