Mac Mini 2011 w Mountain Lion - Dual display issues

Same problem here.

MBP early 2011

With Mountain Lion 10.8.0

My HDMI adapter stoped working.

With Mountain Lion 10.8.1

Both HDMI and VGA adapter stoped working

It is a driver issue with your converter. I have a DisplayLink converter and had similar issues. I downloaded the driver and all is well. http://www.displaylink.com/support/sla.php?fileid=67

i use just hdmi but i am having issues while reboot which even 10.8.2 did not address so i am going to give this link a shot - will keep you posted if it works

I made mention of this before, but I'll repeat it for those who might have missed it. There's something not quite right with the graphics processor selection process in Mountain Lion. Here's what I found out:

On the MacBook Pro, there are two graphics processors, an Intel HD graphics processor which is integrated into the CPU unit, and an AMD Radeon HD6750M, which is a more powerful but more power-hungry discrete chip.

Theoretically, the MBP should automatically switch to the discrete processor when the power adapter is connected (for better performance) and to the integrated processor when operating on battery (for power savings). But quite often, I find that the MBP is incorrectly running on the integrated processor while the power adapter is connected. Why? I don't know. But I do know that when it's running on the integrated unit my HDMI HDTV absolutely will not operate off the MBP Thunderbolt port.

If you don't have visibility on which graphics processor is being used, you don't know why sometimes (or maybe all the time) the HDMI-connected unit isn't working. When I finally installed gfxCardStatus (by Cody Krieger, http://codykrieger.com/gfxCardStatus) I could see when the integrated processor was incorrectly being used instead of the discrete processor. With gfxCardStatus I can manually change back to the discrete processor, and voila! my HDMI unit works again.

This isn't everybody's problem, I know that, but it fixed (and continues to fix) this problem for me. Hopefully this might be of assistance to someone else as well.

Good luck,

chico

The machine will use whatever chip makes the most sense as to what is happening on the computer at the time.

Even if you re plugged in, and your doing some light work, the built in card may be on.

This will help the machine stay cooler, as the charging the machine can heat it up quite some.

identd wrote:

The machine will use whatever chip makes the most sense as to what is happening on the computer at the time.

Even if you re plugged in, and your doing some light work, the built in card may be on.

This will help the machine stay cooler, as the charging the machine can heat it up quite some.

Perhaps that's true. But just now I found it running the power-sipping Intel integrated processor, even though the power adapter was plugged in. I fired up Google Earth and loaded some very processor-intensive KML overlays, making the processor churn for several minutes. The fan came on. But the processor didn't change to the AMD chip. So I had to manually change it over for better performance. If I didn't have a way to see this via gfxCardStatus, I wouldn't have known it wasn't using the more powerful graphics processor even though it should have been.

The evidence shows me something isn't allowing graphics processors to switch as you describe. I realize that's how it SHOULD work, but it doesn't do that properly all the time on my machine.

After I figured this out, I can now watch my HDTV off the Thunderbolt port reliably. Previous to this, Mountain Lion made it very much a hit or miss proposition.

You could always turn off automatic switching in energy saver and it will use the better of the cards.

Also, ASP will show you which one is in use.

gfx status will pause the machines ability to switch back and worth.

Remove it, pram reset, and the use ASP to determine when it switches

identd wrote:

You could always turn off automatic switching in energy saver and it will use the better of the cards.

Also, ASP will show you which one is in use.

gfx status will pause the machines ability to switch back and worth.

Remove it, pram reset, and the use ASP to determine when it switches

I repeat: It wasn't working properly on my machine before I installed gfxCardStatus. That's why I came to this thread in the first place. I tried everything I could think of (PRAM reset included) with no luck.

Automatic switching is off in my Energy Saver preferences, with "Higher Performance Graphics" checked. I always use the power adapter and only go to battery when I move the computer to a different location in the house. But somehow the Intel graphics card gets enabled at some point, and the AMD processor doesn't always come back on when the power adapter is plugged back in. Maybe some other 3rd party software is conflicting, maybe not. I haven't felt the need to do any more troubleshooting after I found a solution that works for me.