I believe the A64 3400+ is a S754 CPU? There are S754 boards that support PCI-E...I don't know that it would be a cost effective upgrade for you though. What motherboard & video card do you currently have?
just to clear up i have 3400+ and am considering upgrading to a pci motherboard that is compatible for it. anyone know of any good, moderately priced boards that support this?
Is your A64 3400+ a socket 754 CPU or a socket 939 CPU? What motherboard (make/model) do you have now? What video card do you have?
PCI-E cards offer only a marginal peformance advantage over AGP. AGP is being phased out, but there are still plenty of decent AGP cards available. Getting a new board & video card (& possibly a new power supply to run it all) simply might not be worth investing in. It *may* make more sense to just get a decent AGP card.
Listing what you hardware you currently have will make it easier for someone to answer your question.