MSI 865PE User Guide - Page 56

RAS# Precharge, Precharge Delay, Burst Length, AGPAperture Size MB

Page 56 highlights

BIOS Setup (clocks) increases the system performance the most while 3 (clocks) provides the most stable performance. RAS# Precharge This item controls the number of cycles for Row Address Strobe (RAS) to be allowed to precharge. If insufficient time is allowed for the RAS to accumulate its charge before DRAM refresh, refreshing may be incomplete and DRAM may fail to retain data. This item applies only when synchronous DRAM is installed in the system. Available settings: 2 clocks, 3 clocks, 4 clocks. RAS# to CAS# Delay When DRAM is refreshed, both rows and columns are addressed separately. This setup item allows you to determine the timing of the transition from RAS (row address strobe) to CAS (column address strobe). The less the clock cycles, the faster the DRAM performance. Setting options: 2 clocks, 3 clocks, 4 clocks, . Precharge Delay This setting controls the precharge delay, which determines the timing delay for DRAM precharge. Settings: 5 clocks, 6 clocks, 7 clocks, 8 clocks, . Burst Length This setting allows you to set the size of Burst-Length for DRAM. Bursting feature is a technique that DRAM itself predicts the address of the next memory location to be accessed after the first address is accessed. To use the feature, you need to define the burst length, which is the actual length of burst plus the starting address and allows internal address counter to properly generate the next memory location. The bigger the size, the faster the DRAM performance. Available settings: 4, 8. AGPAperture Size (MB) This setting controls just how much system RAM can be allocated to AGP for video purposes. The aperture is a portion of the PCI memory address range dedicated to graphics memory address space. Host cycles that hit the aperture range are forwarded to the AGP without any translation. The option allows the selection of an aperture size of 4MB, 8MB, 16MB, 32MB, 64MB, 128MB, and 256 MB. 3-13

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3-13
BIOS Setup
(clocks) in
creases the system per
for
mance th
e most wh
ile
3
(clocks)
provides the most stable performance.
RAS# Precharge
This item controls the number of cycles for Row Address Strobe
(RAS) to be allowed to precharge. If insufficient time is allowed for
the RAS to accumulate its charge before DRAM refresh, refreshing
may be incomplete and DRAM may fail to retain data. This item
applies only when synchronous DRAM is installed in the system.
Available settings:
2 clocks
,
3 clocks, 4 clocks
.
RAS# to CAS# Delay
When DRAM is refreshed, both rows and columns are addressed
separately. This setup item allows you to determine the timing of the
transition from RAS (row address strobe) to CAS (column address
strobe). The less the clock cycles, the faster the DRAM performance.
Setting options:
2 clocks, 3 clocks
,
4 clocks
, .
Precharge Delay
This setting controls the precharge delay, which determines the timing
delay for DRAM precharge. Settings:
5 clocks, 6 clocks, 7 clocks, 8
clocks
, .
Burst Length
This setting allows you to set the size of Burst-Length for DRAM.
Bursting feature is a technique that DRAM itself predicts the address
of the next memory location to be accessed after the first address is
accessed. To use the feature, you need to define the burst length,
which is the actual length of burst plus the starting address and
allows internal address counter to properly generate the next memory
location. The bigger the size, the faster the DRAM performance.
Available settings:
4, 8
.
AGPAperture Size (MB)
This setting controls just how much system RAM can be allocated to AGP for
video purposes. The aperture is a portion of the PCI memory address range
dedicated to graphics memory address space. Host cycles that hit the aperture
range are forwarded to the AGP without any translation. The option allows the
selection of an aperture size of
4MB, 8MB, 16MB, 32MB, 64MB, 128MB,
and
256 MB.