Abit SX7-533 User Manual page 39

Introducing the BIOS
SDRAM RAS precharge time. It can define the SDRAM precharge to ACT command period.
tRP timing value (Precharge time – time from precharge command to when back can be activated).
" DDR RAS to CAS Delay:
Three options are available: 2T ) 3T ) 4T. The default setting is 3T. This item is to set SDR/DDR
SDRAM RAS to CAS delay. It can define the SDRAM ACT to Read/Write command period.
tRCD timing value = RAS to CAS latency + rd/wr command delay
" DDR Write Recovery Time:
Two options are available: 2T ) 1T. The default setting is 2T. This item is to set SDR/DDR SDRAM
write recovery time. This item (bit) controls the number of clock cycles that must occur from the last
valid write operation to the earlist time a new Precharge command can be asserted to the same bank.
When you set it to 1T, tWR duration is 1 clock cycle, etc.
" Timing Constraint Control:
Two options are available: Slow ) Normal. The default setting is Slow. Timing Constraint Control
on DDR SDRAM Back-to-Back write Commands which are issued to different ranks.
" GW Write Mask AGP Request:
Two options are available: Enabled ) Disabled. The default setting is Enabled. When you set to
Enabled, a graphic window write operation will forbid AGP device to access memory until this write
operation is finished. When set to Disabled, AGP request can access memory as usual.
MA Delay 1T/2T Select:
Three options are available: Auto ) MA 2T ) MA 1T. The default setting is Auto. This item will effect
the memory address read/write speed, MA 1T will be the fast selection.
Host To Memory Latency:
Two options are available: Normal ) Fast. The default setting is Normal. This item can adjust the bus
read/write speed between the northbridge and memory.
Advanced Read Prefetch:
Two options are available: Disable or Enable. The default setting is Enable. This item controls the
prefetch caching for PCI slave control, Select Enable will increase the system performance.
AGP Capability:
Two options are available: 4X ) 2X. The default setting is 4X. If you use the older AGP adapter that
does not support AGP 4X mode, you need to set this item to 2X. You can check your AGP adapter user's
manual to know what kind of AGP mode it can support.
AGP Fast Write:
Two options are available: Enable or Disable. The default setting is Disable. If your AGP adapter can
support this function, then you can choose Enable. Otherwise, choose Disable. Enabling this item can
improve your system performance, but it may also decrease system compatibility.
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User's Manual