Re: Feisty -> AMD64 -> Failed to initialize the NVIDIA graphics device PCI:1:0:0
I am experiencing the same issue (or at least symptoms), though without the agpgart conflict, and I have some more info to add.
First of all, my card is an XFX 8600GT.
I first tried installing it on a Fedora Core 5 machine with 32-bit Intels, replacing an ATI card. After running the ATI uninstall script (which seemed sucessful) and installing kmod-nvidia-smp from yum, I was greeted with the blank screen when starting X. I don't have access to the log files from that computer at the moment, but could get them tomorrow.
I then tried it in my home machine, which fits the OP's specs, Ubuntu 7.04, dual-core AMD64. For this test, I just took out my 7900GT and plugged in the 8600, then tried to boot. Once again, it hangs when trying to start X. I then restarted in recovery mode and ran nvidia-xconfig and got the same result. I'll stress that the 7900GT works just fine (with either config) on this computer though. Was it naive of me to think that the swap should work without modification, or what else should I have done?
I haven't tried the 7900GT in the Fedora computer, nor can I yet confirm that the same problem is giving the observed symptoms on both machines, but it does seem interesting that the symptoms span architecture and distribution. Is it still likely to be a BIOS problem if the 7900GT runs without any problems? In his Ubuntu forums post, the OP says he was indeed able to resolve his issue with a BIOS change: his AGP aperture was set to 32MB, and raising it to 64MB apparently fixed things (along with trying lots and lots of software changes). But as my cards are PCI-E, that shouldn't be relevant, right? You suspect some other particular BIOS setting?
The attached log file is from the Ubuntu machine after booting in recovery mode and trying to start X.