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topgunn

macrumors 68000
Original poster
Nov 5, 2004
1,570
2,091
Houston
Here is the situation. When I boot into Windows, my PCIe bus is changed from x16 to x1. When I reboot and load Mac OS again, it is still x1. When I reboot again and go back in to Mac OS, it is finally back to x16.

I have tested this with WinXP, Vista, and Windows 7. I have tested this with the Apple drivers from the Leopard DVD, Snow Leopard DVD and the latest drivers from nVidia.

At first I thought it was because I was loading games and stressing the GPU. Then I noticed it did the same thing without running any 3D games at all. Next I thought it was a temperature issue. So I installed SMC fan control and revved the fans up to max speed and rebooted in to Windows. The fan settings stuck as expected. I rebooted into Mac OS and the PCIe bus was again set to x1.

I am at a loss. My best guess is that this is a firmware bug of some sort. I highly doubt it is because of the OS or driver version due to all of the combinations I have tried. Any ideas?

Also, if it is hardware or firmware based, will Apple even do anything about it? Windows still "works" but just with a very slow GPU.

Curious to see what you all think.
 
Any ideas? Do you think Apple would do anything about this?

By the way, this machine has had the logic board and graphics card replaced at different points since I have had this computer. The problem existed both before and after these parts were replaced.
 
I have now had a case open with Apple about this problem for more than 3 months. They wanted to duplicate the problem in-house but I was told that they don't have an iMac with the 8800 video card. I haven't had an update in close to 2 months. Any ideas on what to do from here? How can I get something done to fix this issue?
 
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