PnP/PCI Configuration

The PnP/PCI Configuration section of the BIOS controls the settings for the motherboard’s PCI slots. This includes the plug-and-play capability of the BIOS. Lets look at those BIOS settings.

• PNP OS InstalledIf all your operating systems support Plug & Play (PnP), select Yes so that they can take over the management of device resources. If you are using a non-PnP-aware OS or not all of the operating systems you are using support PnP, select No to let the BIOS handle it instead. Some say that it is best to leave this option set to No regardless of whether your OS is PNP-capable or not. The reason is that when it is set to No, the BIOS will attempt to resolve any resource conflicts. If it is set to Yes, even if a conflice is detected, the BIOS will ignore it. So, setting it to Yes provide a bit of a safety net, and it will not affect the ability of the OS to perform PNP on its own.

• Reset Configuration Data (Force Update ESCD)
  ESCD (Extended System Configuration Data) is a feature of the Plug & Play BIOS that stores the IRQ, DMA, I/O and memory configurations of all the ISA, PCI and AGP cards in the system (PnP or otherwise). Normally, you should leave the setting as Disabled. If you encounter serious problems with the installation of a new PCI card, this settings can help bail you out. Such a conflict would be serious enough that the OS may not start. If this happens, you can go into the BIOS and enable this option. Next time the PC boots, the BIOS will go and re-configure the settings for all PNP cards. The BIOS will automatically reset this setting to DISABLED next time you boot.
• Resources Controlled By
  Normally, the BIOS controls the IRQ and DMA assignments of all of the boot and PNP devices in the system. When this option is set to AUTO, this is what happens, and the ESCD is the mechanism for doing it. If you set this option to Manual, you will be able to manually assign all IRQ and DMA information, usually via a sub-screen of the BIOS that will enable if you set this option to Manual.
• PCI/VGA Palette SnoopThis option is only useful if you use an MPEG card or an add-on card that makes use of the graphics card’s Feature Connector. It corrects incorrect colour reproduction by “snooping” into the graphics card’s framebuffer memory and modifying (synchronizing) the information delivered from the graphics card’s Feature Connector to the MPEG or add-on card. It will also solve the problem of display inversion to a black screen after using the MPEG card.
• Assign IRQ for VGA
  Many high-end graphics accelerator cards now require an IRQ to function properly. Disabling this feature with such cards will cause improper operation and/or poor performance. Thus, it’s best to make sure you enable this feature if you are having problems with your graphics accelerator card.
• Assign IRQ for USB
  Assigns an IRQ to the USB controller. It enables or disables IRQ allocation for the USB (Universal Serial Bus). If you are using AGP, this shoudl be enabled. If you are not, you can disable this to free up an IRQ.