Ok, the problem is not AMD64 specific, it's K8 GART specific. It seems the Nvidia drivers, both the 1.0-4496 IA32 version, and the 1.0-4499 AMD64 version, fail to allow AGP when the system uses the K8 internal GART (All Athlon64/Opteron systems do. The AGP chipset no longer needs to be supported directly, just the K8 GART and the card that will be the client.)
This is a pretty freaking major bug, that will only get bigger as time goes by and more Linux users get K8 machines. PCI mode is dirt slow! Both my Barton and my 2.8C P4 could manage around 10K fps in glxgears at my res/refresh, but without AGP support, my MORE POWERFUL Athlon64, on a pure 64bit distro can manage a whole whopping 3.3K fps? That's ONE THIRD the speed it runs on a SLOWER machine!! Come on!!?
Just FYI, AGPGART itself is NOT broken, all the DRI cards seem to work fine with the K8 GART. I personally tossed a Radeon 1 in tonight at a friend's suggestion, and got fully accelerated and fully AGP-using graphics. My Radeon 1 is just a tad slow to do much of anything on, though.
Nvidia - Come on! Get in contact with me! my nick @kmfms.com , I'd love to bug test a fixed driver, I just want to use the FIVE HUNDRED DOLLAR GRAPHICS CARD I bought for this reason only! I'f I'd realized that NV's drivers are broken and seem to be unlikely to get fixed soon, I would have saved my cash and left my 9800 Pro in! I got the same accel 2D/video/etc with that card as I am right now!
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