Advantech AIMB-744 Series, User Manual

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AIMB-744 User’s Manual 16
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.
1.10 Memory Installation Procedures
To install DIMMs, first make sure the two handles of the DIMM socket
are in the "open" position. i.e. The handles lean outward. Slowly slide the
DIMM module along the plastic guides on both ends of the socket. Then
press the DIMM module right down into the socket, until you hear a
click. This is when the two handles have automatically locked the mem-
ory module into the correct position of the DIMM socket. To remove the
memory module, just push both handles outward, and the memory mod-
ule will be ejected by the mechanism in the socket.
1.11 Cache Memory
Since the second-level (L2) cache has been embedded into the Intel®
socket 478 Pentium® 4/Celeron™ processor, you do not have to take care
of either SRAM chips or SRAM modules. The built-in second-level
cache in the processor yields much higher performance than the external
cache memories. The cache size in the Intel ® Pentium ® 4 processor is
512/1024 KB. In the Celeron CPU, the cache size is 128/256KB.