If it increases too much much all your pci devices will stop working, eg-LAN, audio, firewire, ect. Back in early socket A days this was a major pain in the @SS as the southbridge was also connected by the PCI bus-basically EVERYTHING stops working (even video, as the AGP clock was tied to the PCI clock) except for processor and memory. Now A64 is on Hypertransport bus so only the PCI devices will go nuts; at least your hdd should still work as the chipset will still function. Unlike processor, memory and graphics overclock there are NO options to stabilise a PCI overclock, and some devices like LAN and firewire are damn sensitive to the PCI clock-sometimes even 1MHz increase also go nuts already.