If they did do something in the firmware to lower noise, its probably slowing down the chipset.
Originally posted by shassard
if you check the asus ftp site, you'll notice that their is a 1004 bios for the a7n8x v1.xx. It includes 200MHz bus support for the new 3200+.
I just upgraded this morning (board rev 1.04), and the bios seems fine although I don't have a 3200+ processor to try out the new bus speed.
After reading a few boards, it looks like the bios probably increases stability for the chipset; Nvidia mentioned that the new bios reduces noise on the board required for higher speed operation.