ASUS P2B User’s Manual 45
IV. BIOS SOFTWARE
IV. BIOS
Chipset Features
Graphics Aperture Size (64MB)
Memory-mapped, graphics data structures can reside in a Graphics Aperture. Leave
on default setting.
Video Memory Cache Mode (UC)
USWC (uncacheable, speculative write combining) is a new cache technology for
the video memory of the processor. It can greatly improve the display speed by
caching the display data. You must leave this on the default setting of UC
(uncacheable) if your display card cannot support this feature or else your system
may not boot.
PCI 2.1 Support (Enabled)
This function allows you to enable or disable PCI 2.1 features including passive release
and delayed transaction. Leave Enabled (default setting) for PCI 2.1 compliancy.
Memory Hole At 15M–16M (Disabled)
Enabling this feature reserves 15MB to 16MB memory address space to ISA expan-
sion cards that specifically require this setting. This makes the memory from 15MB
and up unavailable to the system. Expansion cards can only access memory up to
16MB. The default is Disabled.
DRAM are xx bits wide
If all your DRAM modules have ECC chips (e.g., 8 chips + 1 ECC chips), they are
considered 72bits and the following will be displayed:
If your DRAM modules do not have ECC chips (e.g. 8 chips), they are considered
64 bits and the following will be displayed instead:
Data Integrity Mode (Non-ECC)
Non-ECC has byte-wise write capability but no provision for protecting data integrity in
the DRAM array. EC-Only data errors are detected but not corrected. ECC with hard-
ware scrubbing allows a detection of single-bit and multiple-bit errors and recovery of
single-bit errors. (See section III for more information on DRAM memory modules.)
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Onboard FDC Controller (Enabled)
When Enabled, this field allows you to connect your floppy disk drives to the onboard
floppy disk drive connector instead of a separate controller card. If you want to use a
different controller card to connect the floppy disk drives, set this field to Disabled.