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2011 MBP Radeon 6750M graphics glitch [video]
- Thread starter Neil1138
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Thanks for the link. As for other users... any thoughts on what could be causing this though? Faulty graphics chip hardware, or some kinda v-sync/driver problem?
i have it as well...
what's your panel? have a look: https://forums.macrumors.com/threads/914054/
i don't think the panel has anything to do with it, anyway.
what's your panel? have a look: https://forums.macrumors.com/threads/914054/
i don't think the panel has anything to do with it, anyway.
Information About This Error (and Next Steps)
Hello all - after some extensive testing, I believe I have a handle on how to best reproduce/demonstrate this problem, and a suggestion for those of you who wish to get Apple's attention with it. I personally have the 15" 2.2 MBP, but I believe this issue will show up on any 15" Sandy Bridge MBP. I think that the Radeon 6750M has a variety of driver-related problems that show up in the following ways (the best way to reproduce/test these is to use a program like GfxCardStatus to manually activate either the Intel or Radeon GPU):
1: The screen tearing is normally confined to the top of the screen, and only appears while using the Radeon GPU. If you connect an external display and set the display mode to 'mirror displays' in display preferences, the tearing on the internal display becomes much worse. Try dragging a window around on the screen, and you will see horrible horizontal tearing on the internal display while the external display looks fine. This is the method I used to demonstrate the problem to someone at the genius bar, and I could reproduce the issue on both my MBP and every floor model I tried (all the 15" model). This issue disappears if you force your MBP to use the Intel chip (you may want to close and reopen apps after forcing the Intel GPU, just to ensure you test properly).
2: If you try benchmarking your MBP (I used geekbench), the score will drop substantially if you are both unplugged AND using the discrete graphics. I typically bench around 10100 plugged in or unplugged using the Intel GPU, but if I am using the Radeon, my score while unplugged drops to around 7600. This benchmarking issue only seems to affect users with 8GB of RAM, and has been posted about before on here. I mention this even though it is distinct from the tearing issue because both seem to center around the Radeon GPU being active. Maybe Apple just does this due to power constraints, but in building a case that there are driver issues with the card, it might help to have examples of where the problem manifests instead of just a little screen tearing.
Since buying my machine, I have had the display assembly switched by an Apple-Certified Service Provider from the default low-res glossy to the high-res anti-glare display. The issue showed up exactly the same on both, so I am certain this is not a panel issue. Furthermore, while the video tearing can be seen on the desktop and while playing video (I tested with Netflix, with a non-letterboxed show so some of the video was touching the top of the screen), it does NOT appear in most games. Portal 2 with Vsync enabled does not have ANY tearing, so clearly the GPU is CAPABLE of displaying everything correctly. I also was able to make the issue vanish by connecting an external display and NOT turning 'mirror displays' on. So the issue is almost certainly driver/firmware-based because it only shows up in certain software-related conditions.
I filed an official bug report with Apple, and I would encourage anyone on here who is willing to do the same. Go to https://bugreport.apple.com/ and file a bug for this model of MBP (you will need to register as an Apple Developer, but you DO NOT need to pay to be in the Developer Program to file a bug report). Try reproducing the problem for yourself using an external display set to mirroring, and if you see the problem, explain how to reproduce it in the bug report. Make sure to indicate that this problem does NOT affect the Intel GPU so that they know to have the Radeon 6750M running while they do tests.
Hello all - after some extensive testing, I believe I have a handle on how to best reproduce/demonstrate this problem, and a suggestion for those of you who wish to get Apple's attention with it. I personally have the 15" 2.2 MBP, but I believe this issue will show up on any 15" Sandy Bridge MBP. I think that the Radeon 6750M has a variety of driver-related problems that show up in the following ways (the best way to reproduce/test these is to use a program like GfxCardStatus to manually activate either the Intel or Radeon GPU):
1: The screen tearing is normally confined to the top of the screen, and only appears while using the Radeon GPU. If you connect an external display and set the display mode to 'mirror displays' in display preferences, the tearing on the internal display becomes much worse. Try dragging a window around on the screen, and you will see horrible horizontal tearing on the internal display while the external display looks fine. This is the method I used to demonstrate the problem to someone at the genius bar, and I could reproduce the issue on both my MBP and every floor model I tried (all the 15" model). This issue disappears if you force your MBP to use the Intel chip (you may want to close and reopen apps after forcing the Intel GPU, just to ensure you test properly).
2: If you try benchmarking your MBP (I used geekbench), the score will drop substantially if you are both unplugged AND using the discrete graphics. I typically bench around 10100 plugged in or unplugged using the Intel GPU, but if I am using the Radeon, my score while unplugged drops to around 7600. This benchmarking issue only seems to affect users with 8GB of RAM, and has been posted about before on here. I mention this even though it is distinct from the tearing issue because both seem to center around the Radeon GPU being active. Maybe Apple just does this due to power constraints, but in building a case that there are driver issues with the card, it might help to have examples of where the problem manifests instead of just a little screen tearing.
Since buying my machine, I have had the display assembly switched by an Apple-Certified Service Provider from the default low-res glossy to the high-res anti-glare display. The issue showed up exactly the same on both, so I am certain this is not a panel issue. Furthermore, while the video tearing can be seen on the desktop and while playing video (I tested with Netflix, with a non-letterboxed show so some of the video was touching the top of the screen), it does NOT appear in most games. Portal 2 with Vsync enabled does not have ANY tearing, so clearly the GPU is CAPABLE of displaying everything correctly. I also was able to make the issue vanish by connecting an external display and NOT turning 'mirror displays' on. So the issue is almost certainly driver/firmware-based because it only shows up in certain software-related conditions.
I filed an official bug report with Apple, and I would encourage anyone on here who is willing to do the same. Go to https://bugreport.apple.com/ and file a bug for this model of MBP (you will need to register as an Apple Developer, but you DO NOT need to pay to be in the Developer Program to file a bug report). Try reproducing the problem for yourself using an external display set to mirroring, and if you see the problem, explain how to reproduce it in the bug report. Make sure to indicate that this problem does NOT affect the Intel GPU so that they know to have the Radeon 6750M running while they do tests.
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Ditto. All issues I reported in my previous post (even the RAM thing) are no longer present for me after the update. The machine is working great now.