Intel AIMB-744 System Memory, PCI-X slots 3.3V/5V selection J8, CPU FSB and memory speed

1.8.5 PCI-X slots 3.3V/5V selection (J8)

The AIMB-744 contains a PCI-X 3.3V/5V selection that provide the user to select the operation voltage either 3.3V or 5V. The default setting is 3.3V which close pin1 and pin2. By closing pin2 and pin3, the operation voltage change to 5V.

Table 1.6: PCI-X slots 3.3V/5V selection (J8)

Function Jumper Setting

*3.3V

1-2 Closed

5V

2-3 Closed

1.9 System Memory

The AIMB-744 has four sockets for 184-pin dual inline memory modules (DIMMs) in two separated memory channels. It can operate with single channel or dual channel modules. We recommend to use dual channel mode to provide optimized performance.

All these sockets use 2.5 V unbuffered double data rate synchronous DRAMs (DDR SDRAM). They are available in capacities of 128, 256, 512 and 1024 MB. The sockets can be filled in any combination with DIMMs of any size, giving a total memory size between 128 MB and 4 GB.

Note: System resources such as PCI and AGP cards require phys- ical memory address locations that reduce available memory addresses above 3GB. This may result in less than 4GB of mem- ory being available to the operating system and applications.

1.9.1 CPU FSB and memory speed

The AIMB-744 can accept DDR SDRAM memory chips without parity. Also note: The AIMB-744 accepts PC2100 (DDR266), PC2700 (DDR

333)and PC3200 (DDR 400) DDR SDRAM, depending on the CPU front side bus frequency (FSB). Please refer below table for the relation- ship between the CPU FSB and memory speed.

Table 1.7: CPU FSB and memory speed

AIMB-744 User’s Manual 14