NVDA(OpenGL): Channel exception!

Dear Al,

Yes, I did, and I basicly see two main problems: hardware failure due to insufficient cooling, which is affecting both ATI and NVidia products, and NVidia software issues where this thread is all about.

The first problem, due to Apples decision to let silence prefer over efficient cooling, can be solved using fan control software. As a matter of fact I installed this too, because some other problems, like f.i. hard disk failure or brown spots on TFT screens, are also related to heath buildup.
The second issue however is due to the never ending story that Apple right from the start didn't provide decent software for NVidia graphic cards. Apple writes the driver software, NVidia delivers the chips, and for some reason this deal has never worked like it should.

As far as I know this problem doesn't exist on the PC or Linux platform.

In the graphic industry the Mac-NVidia problem is wellknown and there they try to avoid the Apple-NVidia combination if possible.

Best regards,
Robbert

Anybody tried Snow Leopard yet?

I have not tried Snow Leopard yet. I did try downgrading to Tiger at one point, as others had reported that working, but it did not work for me. Not that it's a solution for me anyway, as I require Leopard.

Snow Leopard caused the issue for me. It did not seem to fix anything regarding this issue. My 2 7300GTs were working just fine until SL so I don't know what to make of all this other than dumping NVIDIA altogether.

D.

For some information regarding this issue please read my following post:

http://discussions.apple.com/thread.jspa?messageID=10124420#10124420

I've just downloaded the Nvidia drivers from
http://www.nvidia.com/object/GeForceMacOSX18.5.2f16.html

and there are some new versions of the GeForce Kext (by looking in the package contents). But I don't get the installer to run 😟

system (10.5.8) version of the GeForce7xxxGLDriv.bundle is
<string>GeForce7xxxGLDriver 1.5.48.6 (17.5.7f10)</string>

download version is
<string>GeForce7xxxGLDriver 1.5.49.0 (18.5.2f16)</string>

can somebody see which version is included with snow leopard?

Message was edited by: Benjamien Mahler

Hmmm, I've looked in the NVIDIA package with pacifist, and my guess is the Snow Leopard drivers are version 1.5.49. But the question is, do they solve the "channel exception" error, which is a software error (correct me if i'm wrong).

@D. Fraser : which error do you get in the console with snow leopard?

Message was edited by: Benjamien Mahler

I had the screen freeze with Channel exception in the Console Log every day many times under 10.5.8 and expect that Snow Leopard will solve the problem.
Unfortunately not and freezes go on.
I decided to try something dangerous. The Console log warns you that the NVDANV50HAL extension is registered many times a day and I think this is abnormal. It looks like my GeForce 8600M GT video card is sometimes lost.
So I deleted the NVDANV40HAL extension which is never used by my video card.
For a week, I had no freeze at all and the NVDANV50HAL extension is registered only one time a day at boot time.
I don't know if this will solve my problem definitely. I cross my fingers.

jnclde83 wrote:
I had the screen freeze with Channel exception in the Console Log every day many times under 10.5.8 and expect that Snow Leopard will solve the problem.
Unfortunately not and freezes go on.
I decided to try something dangerous. The Console log warns you that the NVDANV50HAL extension is registered many times a day and I think this is abnormal. It looks like my GeForce 8600M GT video card is sometimes lost.
So I deleted the NVDANV40HAL extension which is never used by my video card.
For a week, I had no freeze at all and the NVDANV50HAL extension is registered only one time a day at boot time.
I don't know if this will solve my problem definitely. I cross my fingers.

Hmmm, that's interesting. I don't have the 50HAL messages in my system.log, just the 40 ones. And I only see the messages when I'm having issues, not every day.

I have the 50Hal kext on my system, I just don't see those messages in my system.log.

*NVDA(OpenGL): Channel exception! status = 0xffff info32 = 0x3 = Fifo: Unknown Method Error*

My problem only occurs when interacting with Cocoatech's Path Finder on machines that only have an NVIDIA card. I have been tracking this problem and it seems to be caused by switching to Path Finder from another application. It seems to me that my problem has to do with PF since nothing else that requires OpenGL causes any issues. My thread on Cocoatech's forum is here: http://forum.cocoatech.com/showthread.php?t=5393

I am using the latest beta builds of PF and the problem, as of now, is not as pronounced. It still occurs but not as much as it has since upgrading to SL.

The SL GeForce7xxxGLDriver.bundle version is 1.6.0.92 (18.6.5f11)

D.

Installed Snow Leopard on the weekend and tried a few things (playing movies etc) to the temp of the graphics diode high. As expected - strange artifacts began to show up on the screen when invoking expose or simply moving windows.

BUT - no freezes so far! I will report on this further in a week or 2

@D Fraser:

thanks!

same message like me under 10.5.8:
*kernel NVDA(OpenGL): Channel exception! status = 0xffff info32 = 0x3 = Fifo: Unknown Method Error*

I don't use PF, but the problem arises with mine (iMac / NVIDIA GeForce 7600 GT) in Photoshop CS4 (with openGL on), in Call of Duty, and sometimes iTunes screensaver. I can only reproduce it consequently with Photoshop tough. The other apps seems to trigger it at random. I've ordered Snow Leopard, so I'm curious if that will solve the problem.

b

Upgrading to Snow Leopard did NOT fix this problem. I still get my 24" iMac to freeze... Arggg!

When I bought this iMac late in 2006 it came with OS X Tiger. Does anyone know for sure which is the latest version of OS X that does NOT trigger this bug in the nVidia chip ?

10.5.6

Alright, so 10.5.6 it is.

Now, pardon my dumb question, but once I downgrade to stock Leopard (10.5.1?) how can I stop the software update process so that it does NOT go beyond 10.5.6 ?

Thanks much!