Graphics cards can sometimes be too aggressive in holding the bus*, causing problems for other bus-master devices, most notably sound cards. Although most mainboard BIOS Setup programs have an option where you can specify a default PCI latency, many cards ignore or override this setting.
To address this problem, PowerStrip allows you to specify the latency for each bus master device on the PCI bus.
1. PowerStrip menu > Options > Adapter information
2. Uncheck the Read-only checkbox
3. Use the device selector to select the bus master that needs adjustment
4. Change the latency - the value is a multiple of 8
5. Click Apply
Repeat for each bus master.
There aren't any hard and fast rules on appropriate values, but as a general guideline higher values yield better performance at the expense of other devices, while lower values are more appropriate to systems with multiple PCI cards.
*Keep in mind that AGP is a port on the PCI bus, not independent of it.