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graphic card needed for use with external monitor?
- Thread starter cinek
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the amd card must be used, the intel card cannot connect to external displays.
if you attempt to force the intel card you will just get a black screen.
if you attempt to force the intel card you will just get a black screen.
I can confirm that my 17" will NOT run a second display unless the AMD GPU is on. I'm assuming this is not a hardware limitation of the Intel 3000 but rather a block put in place by Apple. Or perhaps the 1920x1200 (internal) + 1920x1080 (external) is too much for the 3000? I don't know, but as of now the discrete card must be running.
I use the intel chip to use my external display on my PC laptop at work, so if the MacBooks cant do external on the intel its a limitation Apple put in place.
If I remember right none of the Core i laptops, including last gen, can use an external on the integrated GPU.
If I remember right none of the Core i laptops, including last gen, can use an external on the integrated GPU.
a 13" with only the Intel graphics can run an external monitor just fine.
a 15" or 17" has to switch to the AMD discrete graphics to run an external because its the only graphics card connected to the display port. The integrated Intel graphics are not in the 15" and 17" config.
a 15" or 17" has to switch to the AMD discrete graphics to run an external because its the only graphics card connected to the display port. The integrated Intel graphics are not in the 15" and 17" config.
Hmm that shouldn't matter. a PC can output any GPU in it to a VGA, DVI or HDMI port. I wonder what would make the TB port and different.
I've been confused about this too and there seems to be a lot of conflicting information.
My 20011 15" switches to the integrated Intel 300 HD fine if I'm using the built-in display (1440x900).
But if I'm connected to my 27" Cinema Display (2560x1440) and force the MBP to the integrated graphics with gfxCardStatus, the display locks up and I have to shut the system down using the keyboard. This is with the MBP closed.
Also, if I'm using the built-in display and have gfxCardStatus set to dynamic switching, my system will always switch to the discrete card (6750M) after a reboot. If I force it to use the integrated graphics, it switches fine and stays there. I'm just curious about why it's switching to the AMD card.
So should I be able to use the integrated graphics to drive my 27" ACD?
My 20011 15" switches to the integrated Intel 300 HD fine if I'm using the built-in display (1440x900).
But if I'm connected to my 27" Cinema Display (2560x1440) and force the MBP to the integrated graphics with gfxCardStatus, the display locks up and I have to shut the system down using the keyboard. This is with the MBP closed.
Also, if I'm using the built-in display and have gfxCardStatus set to dynamic switching, my system will always switch to the discrete card (6750M) after a reboot. If I force it to use the integrated graphics, it switches fine and stays there. I'm just curious about why it's switching to the AMD card.
So should I be able to use the integrated graphics to drive my 27" ACD?
If you'd read the whole thread, you would've noticed a poster said that only the AMD card was connected to the thunderbolt(display) port, since the intel card can't even communicate with an external display, you can't use it. Simple as that.
It's not a software limitation, there are just no "wires" so to speak going from the external display port to the Intel card.
According to post #8 in this thread
https://forums.macrumors.com/threads/1124931/
It is due to the way that the port is physically wired.
https://forums.macrumors.com/threads/1124931/
It is due to the way that the port is physically wired.
Sorry, I missed that this was specific to the 13" earlier. I thought that was conflictig with TXBDan's post.
From what I saw through gfxcardstatus, my external monitor was listed as a dependency, thus forcing it into Radeon 6750M 
sad case, because this is gonna drain my battery. I think Apple should do something about this.
sad case, because this is gonna drain my battery. I think Apple should do something about this.