ASUS P2B-N User’s Manual 53
4. BIOS SETUP
4. BIOS
Chipset Features
16-bit I/O Recovery Time (1 BUSCLK) / 8-bit I/O Recovery Time (1 BUSCLK)
Timing for 16-bit and 8-bit ISA cards, respectively. Leave on default setting.
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, otherwise your sys-
tem 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 DIMMs have ECC (e.g., 8 chips + 1 ECC chip), they are considered
72bits and the following will be displayed:
If your DIMMs do not have ECC (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 memory module array. EC-Only data errors are detected but not corrected.
ECC with hardware scrubbing allows a detection of single-bit and multiple-bit errors
and recovery of single-bit errors. (See 2. System Memory, section III for more infor-
mation on 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.