User`s manual

1.9.1 CPU FSB and memory speed

The PCA-6188 can accept DDR SDRAM memory chips without parity.

Also note: The PCA-6188 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.

The PCA-6188 supports ECC (error checking and correction). Memory

modules with 9 SDRAM chips/side support ECC; The OS boot up time

will become longer while use ECC RAM module, the larger capacity the

time will be longer.

1.9.2 Dual channel configuration

The four DIMM sockets are arranged in two channels: DIMM1 &

DIMM2 in channel A; DIMM3 & DIMM4 in channel B. To enable dual

channel operation, please install a matched pair of DIMMs in DIMM1 &

DIMM3 (green sockets). If additional memory is to be used, another

matched pair of DIMMs have to be installed in DIMM2 & DIMM4 (pur-

ple sockets).

"Matched pair of DIMMs" means: same in speed (DDR266, DDR333,

DDR400), same in size (128MB, 256MB, 512MB or 1GB), same in chip

density (128 Mb, 256Mb or 512Mb and same in CSA latency. Any other

memory configuration will result in single channel memory operation.

Table 1.5: CPU FSB and memory speed

Memory

Speed

Processor FSB frequency Memory speed Outcome

DDR400 Pentium 4 800 MHz 400 MHz

DDR333 Pentium 4 800 MHz 320 MHz

Pentium 4 533MHz 333 MHz

Pentium 4

or Celeron

400 MHz 266 MHz

DDR266 Pentium 4 533 or 400 MHz 266 MHz

Celeron 400 MHz 266 MHz