User`s manual

AIMB-240 Series
64 AIMB-240 Series User’s Manual
system performance because the OS does not need to access the system BIOS much.
The available options are: Disabled, Enabled.
3.5.3.9 Video BIOS Cacheable
This feature is only valid when the video BIOS is shadowed. It enables or disables the
caching of the video BIOS ROM at C0000h-C7FFFh via the L2 cache. This greatly speeds
up accesses to the video BIOS. However, this does not translate into better system
performance because the OS bypasses the BIOS using the graphics driver to access the
video card's hardware directly.
The available options are: Enabled, Disabled.
3.5.3.10 Memory Hole At 15M-16M
Enabling this feature reserves 15MB to 16MB memory address space to ISA expansion
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 available options are: Enable, Disable.
3.5.3.11 Delayed Transaction
This feature is used to meet the latency of PCI cycles to and from the ISA bus. The ISA bus
is much, much slower than the PCI bus. Thus, PCI cycles to and from the ISA bus take a
longer time to complete and this slows the PCI bus down.
However, enabling Delayed Transaction enables the chipset's embedded 32-bit posted
write buffer to support delayed transaction cycles. This means that transactions to and from
the ISA bus are buffered and the PCI bus can be freed to perform other transactions while
the ISA transaction is underway.
This option should be enabled for better performance and to meet PCI 2.1 specifications.
Disable it only if your PCI cards cannot work properly or if you are using an ISA card that is
not PCI 2.1 compliant.
The available options are: Enabled, Disabled.
3.5.3.12 Delay Prior to Thermal
When you system temperature higher, you can set the DRAM access time slowdown
between on 4 min – 32 min delay.
The available options are: 4 Min, 8 Min, 16 Min, and 32 Min.
3.5.3.13 AGP Aperture Size (MB)
Select the size of Accelerated Graphics Port (AGP) aperture. The aperture is a portion of
the PCI memory address range dedicated for graphics memory address space. Host cycles
that hit the aperture range are forwarded to the AGP without any translation.
The available options are: 4, 8, 16, 32, 64, 128, 256.
3.5.3.14 On-Chip VGA
This item is enabled as the onboard VGA is used.
The available options are: Enabled, Disabled.
3.5.3.15 On-Chip Frame Buffer Size
This item is to select the amount of system memory that will be utilized as internal graphics