I noticed the Asus A7V. I have the exact same board.
There are some things you need to know about the Via chipset. Windows performs poorly with the Via chipset default drivers. Especially the AGP handling is pretty @#$%&, but other areas are also affected.
I am pretty certain that the faster your GFX card is, and hence faster and larger AGP transfers, the more your performance will be hampered by this. I also first noticed real problems when I exchanged my TNT2 Ultra with a GF2 GTS.
You can solve the problems by downloading the Via 4-in-1 drivers package, as it installs a driver with a different routine for handling AGP transfers.
Here's a download link
[
downloads.viaarena.com]
Go here if you need more information:
[
www.viaarena.com]
It's only after we've lost everything, that we are free to do anything.