Re: how to switch to Nvagp 1 ?
My understanding is that you have 64-bit kernel? If so then removing agpgart is pretty easy:
1) Processor type and features -> uncheck K8 GART IOMMU support
2) Character devices -> uncheck /dev/agpgart (AGPGART Support) ----> this should be done automatically when you do step 1)
This works well in vanilla kernels, specific distro may add extra dependencies.