Clueless GPU Questions

[Avroe]

I have some questions and I am not even sure how to look up the answers.  I own a laptop. I have never owned a desktop with dedicated graphics and I don't know a lot about computers, so this might sound really stupid.

 

My laptop has a dedicated graphics card as well as integrated graphics.  I can switch which GPU is used for a particular program in the NVIDIA control panel.

 

I was thinking about how this works on a desktop computer.  I have heard that if the monitor is plugged in to the graphics card, the computer will use the dedicated GPU.  If the monitor is plugged into the motherboard, it will use the integrated graphics in the CPU (assuming it has integrated graphics, which I think most do).  My questions are:

 

1.  Are the dedicated GPU and integrated GPU running at the same time?  [This might answer the other questions]

 

2.  Assume that I have a desktop computer with a dedicated GPU, and the monitor is plugged into the GPU.  If I am running a process that is graphics intensive and I unplug the monitor from the GPU, what will happen?  Obviously the monitor will read 'no signal', but what will happen to the process?   

3.  What if a have a desktop and I have two monitors.  Can one monitor be plugged into the motherboard and the other plugged into the GPU at the same time?  If so, I assume that the performance will be much different.  

 

Thanks in advance.

 

[Firewrath9]

1. y, but if nothing is plugged in, its idle and the clock speed is bascially 0, so no power draw (IIRC)

 

2. the process will still continue (IIRC)

 

3. Y, but it won't be more efficent. running the desktop is SUPER easy, you could run 4 8k monitor off a single gpu, and it'd be 5w more than a  single 1080p

 

[Jurrunio]

5 minutes ago, Avroe said:

1.  Are the dedicated GPU and integrated GPU running at the same time?  [This might answer the other questions]

Yes and no, depends on how the BIOS is configured.'

 

6 minutes ago, Avroe said:

2.  Assume that I have a desktop computer with a dedicated GPU, and the monitor is plugged into the GPU.  If I am running a process that is graphics intensive and I unplug the monitor from the GPU, what will happen?  Obviously the monitor will read 'no signal', but what will happen to the process?   

Still, depends on the BIOS configuration. Most let you choose the preferred GPU (PCIe or iGPU).

 

7 minutes ago, Avroe said:

3.  What if a have a desktop and I have two monitors.  Can one monitor be plugged into the motherboard and the other plugged into the GPU at the same time?  If so, I assume that the performance will be much different.  

You can do that but the performance stays the same. Rendering a desktop is hardly any work even for Intel's debug graphics.

[schwellmo92]

12 minutes ago, Avroe said:

1.  Are the dedicated GPU and integrated GPU running at the same time?  [This might answer the other questions]

The iGPU is always running, it is responsible for drawing the frames, the dGPU may be called upon to do some of the grunt work but ultimately hands off the frames to the iGPU to draw to the screen.

 

More info: https://en.wikipedia.org/wiki/Nvidia_Optimus

[Jurrunio]

On 2/26/2019 at 6:48 PM, schwellmo92 said:

The iGPU is always running, it is responsible for drawing the frames, the dGPU may be called upon to do some of the grunt work but ultimately hands off the frames to the iGPU to draw to the screen.

 

More info: https://en.wikipedia.org/wiki/Nvidia_Optimus

btw Optimus is laptop specific