Asus DiGiMatrix - Manual (Page 134)

5-16 Chapter 5: BIOS Information
5.4.1 Chip Configuration
SDRAM Configuration [By SPD]
This parameter allows you to set the optimal timings for items 2–5,
depending on the memory modules that you are using. The default setting
is [By SPD], which configures items 2–5 by reading the contents in the
SPD (Serial Presence Detect) device. The EEPROM on the memory
module stores critical information about the module, such as memory type,
size, speed, voltage interface, and module banks.
Configuration options: [User Defined] [By SPD]
SDRAM CAS Latency [2.5T]
This item controls the latency between the SDRAM read command and
the time the data actually becomes available. Configuration options: [2.5T]
[2T] [1.5T] [3T]
SDRAM RAS to CAS Delay [3T]
This item controls the latency between the SDRAM active command and
the read/write command. Configuration options: [3T] [2T] [4T]
SDRAM RAS Precharge Time [3T]
This item controls the idle clocks after issuing a precharge command to
the SDRAM. Configuration options: [3T] [2T] [4T]
The SDRAM parameters (items 2~5) is user configurable only when you
set the SDRAM Configuration to [User Defined].