kingking, what you are saying has no sense. Are you sure your mobo and your 3d card handle AGP 4X ? If you are sure, then it isn't a driver option, it must be a bios option and otherwise there are many third party prog that can enable it if it is not enabled by default.
I made some test with the new 21.81 drivers with my Geforce DDR :
In 3DMark2001, a 5% increase in hardware T&L and a 5% increase in software T&L (compared with 12.41 drivers but weren't the fastest drivers)
In 3DMark2000, a 5% increase in hardware T&L and a 15% increase in software T&L (compared with 12.41 drivers)
The results in 3DMark2000 are very interesting, it's the first time that some drivers after 6.XX and 7.XX have speed increase (hard T&L is equal to results with the best 7.XX drivers, and soft T&L is the best never seen).
So, in conclusion, some results are equal to results already seen with other drivers, but there is a real increase of software T&L in 3DMark2000,so PC games which were programmed for a version prior to DirectX8 should benefit of this increase (it wasn't expected).
Now, a precision : I don't want to see somebody saying that ePSXe is faster with these drivers. Indeed, emu speed is CPU dependant, and gfx quality is GPU dependant.