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PCI latency behavior for selected I/O Devices

When people first started looking into the PCI latency settings on their PCs, they discovered that while some motherboard BIOS allowed the PCI latency to be set to a specific value, the device drivers for the devices would often set to their own preferred value on startup, making the PCI latency setting for a device impossible to control without a program such as Double Dawg. This leads to the natural question: "How do the device drivers handle the PCI latency settings?"

Martin Walker of SOS Magazine asked SOS forum members to perform some experiments to determine how the drivers for their devices manipulated the PCI latency setting, and he did some testing with his own gear as well. He has graciously provided us with this summary of the latency-setting behavior of some popular I/O devices.

DEVICES THAT ADOPT THE DEFAULT BIOS OR MOTHERBOARD VALUE:

GRAPHICS CARDS

SOUNDCARDS

DEVICES THAT FORCE THEIR OWN PCI LATENCY TIMER VALUE:

GRAPHICS CARDS

SOUNDCARDS