[mythtv-users] Why is OpenGL video renderer overheating my GPU?

Michael T. Dean mtdean at thirdcontact.com
Tue May 8 19:28:16 UTC 2012


On 05/08/2012 03:01 PM, Gabe Rubin wrote:
> On Tue, May 8, 2012 at 11:56 AM, Michael T. Dean wrote:
>> On 05/08/2012 02:43 PM, Gabe Rubin wrote:
>>> Hi List,
>>>
>>> I have an Nvidia 220 card with a fan and heatsink that takes up one
>>> slot.  I don't have that many slots in my motherboard and can't leave
>>> any open next to the video card.  When the system is idle (i.e., just
>>> displaying the menu screen but not playing video), the GPU temp is 62
>>> C (as reported by nvidia-smi).  This seems high to me.  It also
>>> reports the fan speed at 0%, but I can tell the fan is on by visual
>>> inspection.
>>>
>>> I have long ago given up on being able to use VDPAU with this card as
>>> it causes the temperature to raise above 100 C and the system shuts
>>> down soon after.  The temperature of my motherboard and my CPU are
>>> within reasonable range when this happens.  With the upgrade to .25, I
>>> am trying the OpenGL renderer, but that also raises the GPU
>>> temperature to a temperature where my computer will shut off, so I
>>> really can only use the "High Quality" playback mode which I believe
>>> uses XVideo and ffmpeg.
>>>
>>> As said, I can't remove the PCI card that is the next slot (a smallish
>>> firewire card that, although close to the heatsink of the video card,
>>> there is a little space between the two) and the other PCI slot is
>>> taken up with my PVR-350 card.
>>>
>>> First, is this type of overheating common with these cards using the
>>> OpenGL renderer?
>>
>> I'll just say that the OpenGL video renderer is significantly less
>> efficient/more resource intensive than the VDPAU renderer.  So, if VDPAU
>> rendering was causing overheating, I'm not surprised the OpenGL rendering
>> does, too.
>>
> Thanks, Mike.  Just to be clear, both the OpenGL and VDPAU renderers
> uses the GPU to do the decoding whereas XVideo and ffmpeg use the CPU
> and that is why the latter does not overheat my GPU?

With VDPAU rendering, you can choose to use either VDPAU decoding or 
"standard" (ffmpeg) decoding.

With OpenGL rendering, you can only use standard decoding.

You'd be better off testing VDPAU rendering with ffmpeg decoding if you 
want low-GPU resource usage.  It will likely perform about the same as 
ffmpeg decoding with Xv rendering, but you'll get the nice, full-size 
OSD (and try with VDPAU and non-VDPAU deinterlacers).

Mike


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