Snow Leopard Freezing showing GPU Debug in Console

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Level 1

42 points

Snow Leopard Freezing showing GPU Debug in Console

I recently updated my iMac from Leopard to Snow Leopard and it began to freeze. I have reset PRAM, SMC, fixed the fonts and looked for anything suspicious in the console. When it freezes there is no obvious crash. It freezes in Safari, Finder and even in Console. The mouse moves, but I cannot do anything. Last freeze shows the time machine icon in mid spin. Console reports npvhash=4095 then GPU Debug info start and hundreds of lines of information. I had this happen on an older machine and the video card was failing.

There is so much chatter about this being related to Snow Leopard, I am wondering if I upgrade to Lion it will all go away?!?

How can I tell if indeed the video card is bad? It is out of warranty and I would like to do as much trouble shooting on my own as I can before, I take it in.

We did not see quite the same behavior in Leopard. Just endless beachball spinning and a few forced restarts. I figured a good clean out of caches, etc would solve the problem along with an OS update.

Thanks for any help and advice in advance,

Debbie

Posted on Dec 7, 2011 5:02 AM

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Answer 1

Dec 7, 2011 6:08 AM in response to singerdf

I had the same problem before upgrading to Lion. That started some point back when I installed one of the latest 10.6 combo update. (Anyway I always use combo update).

Nothing has changed after Lion was installed, and I installed Lion from scratch, on a formatted disk.

In my case I had and have random GUI hangs. Can happen once a week or once a month.

I want to point out that only the GUI doesn't work. I can move the curson around but nothing else.

I usually enable "Remote Login" and "Screen sharing" in every Mac I own, so that I can do a clean shutdown via SSH or Screen sharing using another computer on the same network.

When the GUI does not respond I can only SSH to the iMac, do whatever I want with the CLI, but the only way to get back the graphical interface to work is to issue a sudo shutdown -h now that can take as long as 10 minutes before completely shutting down the Mac.

Unfortunately I didn't find any solution until now. In my opinion there is something relating to the graphic card, perhaps driver or a hardware bug in the GPU itself.

My /var/log/kernel.log file shows the same long debug list as yours

Dec 6 09:43:46 rfc-1918 kernel[0]: ** Device in slot: SLOT--1 **

Dec 6 09:43:46 rfc-1918 kernel[0]: ** GPU Debug Info Start **

Dec 6 09:43:46 rfc-1918 kernel[0]: 0x000094c8

Dec 6 09:43:46 rfc-1918 kernel[0]: 0x000000d6

Dec 6 09:43:46 rfc-1918 kernel[0]: 0x00000001

Dec 6 09:43:46 rfc-1918 kernel[0]: 0x00000018

Dec 6 09:43:46 rfc-1918 kernel[0]: 0x0000d062

Dec 6 09:43:46 rfc-1918 kernel[0]: 0x00000001

Dec 6 09:43:46: --- last message repeated 1 time ---

...

Dec 6 09:44:05 rfc-1918 kernel[0]: 0x0000217f

Dec 6 09:44:05 rfc-1918 kernel[0]: 0x00000000

Dec 6 09:44:05: --- last message repeated 1 time ---

Dec 6 09:44:05 rfc-1918 kernel[0]: 0x80000000

Dec 6 09:44:05 rfc-1918 kernel[0]: ** GPU Debug Info End **

My iMac is

iMac7,1 - Intel Core 2 Duo 2 GHz with ATI,RadeonHD2400

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Answer 2

singerdf Author

Level 1

42 points

Dec 7, 2011 8:03 AM in response to Alberto Ravasio

Thank for the reply. My iMac is the only computer in the house. So remote shutdown will not help. My iMac is about 4 1/2 years old and up until about 2 months ago not often used. I would like to be able to determine if the video card has gone bad since that is what all of those errors imply.

At this point, I am going to hold tight and not upgrade to Lion. That seems like it will only add another layer of issues.

What are you going to do? My machine is really useless at this point, as I need to do a hard restart every 15 minutes.

Thanks in advance for any suggestions,

Debbie

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Answer 3

singerdf Author

Level 1

42 points

Dec 7, 2011 5:16 PM in response to Alberto Ravasio

Adding a couple more pieces:

I created a test account and tried that. Frozen while in console and then after force restart at safari start up. This time I do not see the GPU debug when I got console to work. I could not find anything to lead me in a direction to suggest the cause.

I have now booted into Safe Mode. Console reported lots of issues with Flash and I figured I needed to update that. I also repaired permissions again with lots of Java errors. Java should update throught Software update and nothing comes through.

I need to know more about what Safe Mode suggests when things no longer freeze there. I understand only apple stuff is on and only the minimal amount.

Looking to learn and get some insight.

thanks,

Debbie

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Answer 4

Dec 8, 2011 3:00 AM in response to singerdf

singerdf wrote:

I need to know more about what Safe Mode suggests when things no longer freeze there. I understand only apple stuff is on and only the minimal amount.

This is what Safe Mode is.

In particular what let your computer run normally in this situation is that many of the kernel extensions (aka drivers) are not loaded.

That also means that your Mac is not running at its best performances.

The good news is that at least runs.

I don't know how much this can help in determine the culprit, but have you run Apple Hardware Test?

The first Mac OS X Install Disc that came with your iMac, also contains the Apple diagnostic.

Insert the disc. Turn on the computer, and press D until the diags starts. Follow the on screen instructions to run the tests.

A brief note before ending this post.

Yesterday evening I was watching a streaming video in Google Chrome. When I installed Lion, I purposely didn't install Adobe Flash Player. So I use Google Chrome that has Flash Player incorporated inside the program itself to display internet sites with Flash contents.

After about twenty minutes the screen freezed. The mouse cursor turned into the "spinning beachball of death". The audio continued to play normally.

The /var/log/kernel.log file, uncovered the usual bunch of lines relating to the GPU

Dec 7 21:22:27 rfc-1918 kernel[0]: ** Device in slot: SLOT--1 **

Dec 7 21:22:27 rfc-1918 kernel[0]: ** GPU Debug Info Start **

Dec 7 21:22:27 rfc-1918 kernel[0]: 0x000094c8

Dec 7 21:22:27 rfc-1918 kernel[0]: 0x000000d6

Dec 7 21:22:27 rfc-1918 kernel[0]: 0x00000001

Dec 7 21:22:27 rfc-1918 kernel[0]: 0x00000018

...

Dec 7 21:22:46 rfc-1918 kernel[0]: 0x00000000

Dec 7 21:22:46 rfc-1918 kernel[0]: 0xc0016900

Dec 7 21:22:46 rfc-1918 kernel[0]: 0x0000008f

Dec 7 21:22:46 rfc-1918 kernel[0]: ** GPU Debug Info End **

About your question, "What I am going to do".

Well. As I wrote, this issue is not so frequent in my case. Also I planned to buy a new iMac next year around march.

But I sincerely hope next Lion update (10.7.3) could patch this misbehaver.

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Answer 5

singerdf Author

Level 1

42 points

Dec 8, 2011 3:34 AM in response to Alberto Ravasio

Thank you for the insight. I forgot to mention that one of the first things I did was run AHT. Did not find anything. In my experience it never does.

Looks like I am headed to an AASS.

Have a great day,

Debbie

Did not know about Chrome. That may be worth trying.

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Answer 6

singerdf Author

Level 1

42 points

Dec 9, 2011 2:33 PM in response to singerdf

Latest update,

Some chatter that this all could be caused with bad fonts. I ran validate fonts today and cleared everything that was flagged. All ttf. Restarted and looked in the log. Nothing showed and I was able to run video, open word felt good. even put the computer to sleep and woke up successfully.

Went away for awhile, came back logged onto safari and tried to go to weather.com. Screen went black while trying to load and I was forced to restart.

I am reallly at a loss now.

Will keep my thinking cap on.

Debbie

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