Many BIOS implementations contain an array of warning beeps to alert the user to problems. Award say that any other beep may indicate a RAM problem. This is tricky and there are many conflicting opinions on this. The North Bridge is, amongst other things, responsible for AGP functions. Thus the AGP clock is related to the external clock of your CPU, not the PCI clock.
Computers emit electrical noise, which can be commonly heard as radio interference.
This setting modulates or varies the bus speed around the setting selected in the BIOS, ensuring that the computer does not emit radio interference at a continuous frequency. AGP cards work by dynamically allocating system memory to the video card. The GART transfers graphics data from system memory, to video memory. In actual fact the system memory can be fragmented, but the GART maps it as one contiguous block. Precharge is the amount of time in ns. that the RAS and CAS lines must be inactive before a fresh memory access can talk place.