I'm running an Asus P4P800 SE MB with an Intel 3.0 ghz processor. Video card is a NVidia 6800 GT.

I've had no problems installing NVidia drivers until I upgraded my motherboard and processor to the 3.0 ghz I currently have.

What I first noticed is that I was having "IRQ not found" errors on boot. I found that Linux kernel 2.6 doesn't like 3 ghz processors. When booting to a 2.4 kernel at least I could get to a login... with 2.6 kernels it froze at the IRQ error message.

I updated my BIOS on the motherboard and now I can boot to a 2.6 kernel. Weird but that seemed to fix the problem with IRQ's.

My remaining problem is that the NVidia installer tells me I don't have the correct kernel source installed when I try to install the NVidia drivers. My current kernel is 2.6.8.1-12mdk. The source code does indeed match the current kernel but the NVidia installer disagrees.

Has anyone run across this and if so, is there a fix?

What does your /usr/src/linux symlink point to? Because that's where things look to find your current kernel source.

The symlink points to the proper source code directory. I've also used the switch "--path-to-kernel-source" with the same result.

You have to setup the BIOS to set IRQ instead letting the OS doing it. By default motherboards have it set to OS because they assume you are going to install Windows.

For the nVidia installer, it could be that in /usr/src/linux/Makefile there is a value custom for the EXTRAVERSION. You may want to change it to match the version of your kernel when running "uname -r".

Thanks Electro but I think it's something more complex than setting the BIOS to non plug and play O.S.

It's set to non-plug-and-play.

The only thing that's really changed from a working NVidia install and non-working is the upgrade from 2.4 ghz processor to 3.0 ghz processor.

Has anyone been successful in getting NVidia drivers to install on a 3.0 ghz system???

Upgrading a processor using the same brand has nothing to do how the software works. If you had the nvidia module already installed, there is no need to re-install it after the processor upgrade. The problem you are having is a software problem not hardware.

If you do not want to edit /usr/src/linux/Makefile, uninstall the kernel souce code and then re-install it. If you have updated the kernel, find the source code that matches your kernel version you are using and install it. You may have to change the path that /usr/src/linux points to.

Unfortunately I have to disagree. The only change made was the processor and motherboard. All worked well until that change. There are also known problems with 3 ghz processors and 2.6 kernels.

Since upgrading my MB Linux (including Suse and Slack) have a rough time detecting the video card. Once I updated to the latest Asus MB BIOS the detection of the video card is successful but still... drivers won't compile. Perhaps there's a combination of hardware and software issues?

Again the processor and motherboard has nothing to do with installing software or compiling if the brand of the processor was the same. You want to be stubborn to not look if its a software problem thats your choice.

You can re-install Slackware, Suse, Mandrake, Fedora. You will the same problem over and over again if its a software problem.

I can not find anything that deals with your problem.

At the risk of shameless self promotion, you might want to try the Santa Fe Linux Live CD
to see what it does. It autodetects and configures the nVidia binary driver at boot. Then
you can use the different CD boot options to figure out exactly what hardware is giving
you trouble. In particular, the oddly named SantaFeAMD boot options will disable apic,
acpi, and will force the use of the bios irq table. If it does work, then its not a hardware
issue.

The next culprit I saw building Santa Fe was the use of thread safe libraries. I had to
manually remove the libtls libraries, rebuild the driver, remove them again, then ldconfig
the system before I built the iso. Otherwise, the kernel module that worked on the
last boot wouldn't load on the next boot. Of course this was under a 2.4. kernel so I'm
not sure exactly whats changed for 2.6 but its an idea.

The iso is at http://www.santafelinux.com

Rafael
Author, Santa Fe Linux