Fujitsu Siemens Computers Fujitsu-Siemens PC - Manual (Page 31)

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for other cards, e.g. multimedia, TV card, modem, the
PCI slots are available. The trend is towards
PCI Express X1.
Slots for memory modules to equip the working memory, so-called
DIMM sockets (abbreviation for "Dual In-Line Memory Modules",
memory modules with two rows of contacts) are also components
of the motherboard. The memory banks can be equipped with the
following memory modules:
• SD RAM, 168 pin (Synchronous Dynamic Random Access
Memory). This memory type synchronises itself with the
system clock, which controls the processor. This prevents
delays when accessing the memory. It works in
synchronisation with the external CPU clock.
• R-DRAM (Rambus-Dynamic Random Access Memory) also
known as RIMM (Rambus Inline Memory Module). This
memory uses a special serial memory organisation, which was
developed by the company RAMBUS. With this principle, the
R-DRAM modules must be placed in pairs. Empty RIMM slots
have to be populated by so-called CRIMMs (Continuity RIMM).
The CRIMMs prevent an interruption in the signal lines, which
are a serial connection in a RAMBUS interface, and therefore
ensure that the direct RAMBUS channel functions correctly. If
you want to upgrade the system memory at a later date, you
can remove the CRIMMs and replace them with RIMMs.
When installing RIMMs, you must observe certain rules, in
order to achieve optimum system performance.
The RIMM slots are divided into two banks:
• Bank 0 (RIMM slots 1 and 2)
• Bank 1 (RIMM slots 3 and 4)
Bank 0 must always be populated first, in order to ensure that
RIMMS are installed in RIMM slots 1 and 2. The memory
configuration (speed, number of chips, size and density) of the
RIMMS installed in Bank 0 and Bank 1 must be identical.
• DDR SDRAM, 184 pin (Double Data Rate Synchronous
Dynamic Random Access Memory). This memory type uses a
technology that works with both sides (flanks) of a clock pulse