GTaero40
1 Copper

E6420 Lists Both Intel GPU and nVidia GPU in the Device Manager. Which is being used?

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Hello all, 

Recently acquired a Latitude E6420.  Apparently my machine is the nicer variant, as it has an i7, 8GB of RAM, and an nVidia NVS 4200M GPU.  After loading all of the drivers, I headed over to device manager too make sure everything was in check.  This is when I noticed that my machine has both "Intel Graphics 3000" and "nVidia NVS 4200M" Listed under graphics adapters.  As both are recognized and both are apparently enabled, how do I know which is being used?  Do they work together? Apparently the NVS has better performance, so I'd like the system to default to this if possible.  Quite confused about the situation, any help/ insight would be much appreciated!

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jphughan
5 Tungsten

RE: E6420 Lists Both Intel GPU and nVidia GPU in the Device Manager. Which is being used?

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Google "NVIDIA Optimus".  Basically, the system defaults to the Intel GPU in order to save battery life when there is no graphic-intensive work going on that would be enhanced by having the NVIDIA GPU active.  In many systems it's also the only GPU physically wired to the display outputs.  When the performance demand increases, e.g .when playing a game, then the NVIDIA GPU is activated and acts as a render-only device, doing the heavy lifting and then passing completed frames to the Intel GPU for output to the displays themselves.  In general, this system works well (and it continues to get better with newer drivers), but there are times when the automatic mechanism does not select the desired GPU.  In those cases, as ejn63 said, you can use the NVIDIA Control Panel to force a particular GPU to be used when a certain application is executed.  You may also notice that if you right-click an application shortcut (at least on the desktop, not sure about the Start menu), you'll see an option that says "Run with graphics processor" and then allows you to select the Intel or NVIDIA GPU.  That is a handy way to choose a specific GPU on a faster, per-execution basis as compared to storing a persistent profile in NVIDIA Control Panel.

However, I would recommend that you just use your system and not worry too much about that unless you see poor performance.  In that case, try manually forcing the application to run on the NVIDIA GPU, and if that improves things, then set a profile if needed. Otherwise, let the system do what it's designed to do, because in most cases it's likely to will do a better job than you. 🙂

4 Replies
8 Krypton

RE: E6420 Lists Both Intel GPU and nVidia GPU in the Device Manager. Which is being used?

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You chose the GPU on a per-application basis with the nVidia control panel.  The Intel GPU is the hardware default - that cannot be changed.

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jphughan
5 Tungsten

RE: E6420 Lists Both Intel GPU and nVidia GPU in the Device Manager. Which is being used?

Jump to solution

Google "NVIDIA Optimus".  Basically, the system defaults to the Intel GPU in order to save battery life when there is no graphic-intensive work going on that would be enhanced by having the NVIDIA GPU active.  In many systems it's also the only GPU physically wired to the display outputs.  When the performance demand increases, e.g .when playing a game, then the NVIDIA GPU is activated and acts as a render-only device, doing the heavy lifting and then passing completed frames to the Intel GPU for output to the displays themselves.  In general, this system works well (and it continues to get better with newer drivers), but there are times when the automatic mechanism does not select the desired GPU.  In those cases, as ejn63 said, you can use the NVIDIA Control Panel to force a particular GPU to be used when a certain application is executed.  You may also notice that if you right-click an application shortcut (at least on the desktop, not sure about the Start menu), you'll see an option that says "Run with graphics processor" and then allows you to select the Intel or NVIDIA GPU.  That is a handy way to choose a specific GPU on a faster, per-execution basis as compared to storing a persistent profile in NVIDIA Control Panel.

However, I would recommend that you just use your system and not worry too much about that unless you see poor performance.  In that case, try manually forcing the application to run on the NVIDIA GPU, and if that improves things, then set a profile if needed. Otherwise, let the system do what it's designed to do, because in most cases it's likely to will do a better job than you. 🙂

GTaero
1 Nickel

RE: E6420 Lists Both Intel GPU and nVidia GPU in the Device Manager. Which is being used?

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Thanks a lot! This was very informative and I now understand (To a degree) what is going on.  This is probably a stupid question, but can I disable the Intel GPU via device manage to allow the nVidia card to work full time?  I wouldn't necessarily want to do this, but when watching youtube in 1080p60 it may be handy, as it appears the intel HD GPU isn't quite able to handle that.  If not, I will just use the nVidia control panel as you both said above.

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8 Krypton

RE: E6420 Lists Both Intel GPU and nVidia GPU in the Device Manager. Which is being used?

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No - you can't.  The nVidia GPU is a co-processor - it has no physical connection to the display panel.  All video data passes through the Intel GPU on its way to your eyes -- if you disable the Intel GPU, you'll have no image at all.

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