BIOS Setup
3-19
PCI Latency Timer (clock)
This feature controls how long each PCI device can hold the bus before an-
other takes over. The larger the value, the longer the PCI device can retain
control of the bus. As each access to the bus comes with an initial delay before
any transaction can be made, low values for the PCI Latency Timer will reduce
the effective PCI bandwidth while higher values improve it.
Primary Graphics Adapter
This item specifies which VGA card is your primary graphics adapter. Settings:
PCI
and
AGP
.
PCI Slot 1/6, 2/5, 3, 4 IRQ Priority
These items specify the IRQ line for each PCI slot. Settings:
3, 4, 5, 7, 9, 10, 11
and
Auto
. Selecting
Auto
allows BIOS to automatically determine the IR line
for each PCI slot.
Set IRQs to PCI or ISA
Press <Enter> to enter the sub-menu and the following screen appears:
IRQ 3/4/5/7/9/10/11/14/15
These items specify the bus where the specified IRQ line is used.
The settings determine if AMIBIOS should remove an IRQ from the pool
of available IRQs passed to devices that are configurable by the system
BIOS. The available IRQ pool is determined by reading the ESCD NVRAM.
If more IRQs must be removed from the IRQ pool, the end user can use
these settings to reserve the IRQ by assigning an
ISA/EISA
setting to it.
Onboard I/O is configured by AMIBIOS. All IRQs used by onboard I/O
are configured as
PCI/PnP
. If all IRQs are set to ISA/EISA, and IRQ 14/15
are allocated to the onboard PCI IDE, IRQ 9 will still be available for PCI
and PnP devices. Available settings:
ISA/EISA
and
PCI/PnP
.
