IBM NetVista Hardware Maintenance Manual page 20

When installing or replacing RIMMs, take the following information into
consideration:
v RIMM connectors do not support dual inline memory modules (DIMMs)
v Use only PC600 or PC800 RIMMs.
v RIMMs must be installed in pairs. The RIMMs installed in a RIMM connector
v Any connector that does not have a RIMM installed must have a continuity
v Install only ECC RIMMS to enable ECC. If ECC and non-ECC memory are used
The following matrix cross-references the name of the computer (printed on the
logo) and the size, speed, and type of memory modules supported in the
computer.
Note: RAMBUS inline memory module (RIMM) is used in the type 6838 and 6848
Supported RIMM memory configuration
Types 6838 and 6848 have two memory channels with two memory sockets for
each channel, making a total of four RIMM memory sockets. RIMM sockets must
have a RIMM memory module or a C-RIMM (RIMM Continuity module) installed.
There can be no empty RIMM sockets. RIMM sockets must contain either a RIMM
or a C-RIMM. At least one socket from each memory channel must have a RIMM
memory module installed.
v If new memory is to be added in a memory channel, remove a C-RIMM and
v If memory is to be removed from a memory channel, remove the RIMM and
12
IBM NetVista Type 6838, 6848: Hardware Maintenance Manual
pair must be of the same speed, and size.
RIMM (C-RIMM).
together, the memory will function as non-ECC memory.
Note: If PC600 and PC800 RIMMs are used together, all memory will function at
the speed of the slowest RIMM.
Memory placement for 4-RIMM Memory Card
Pair 1
1 2
2 RIMMs RIMM RIMM
4 RIMMs RIMM RIMM
Note: Memory must be installed in matched pairs.
computers. RIMM modules are not compatible with SIMM or DIMM
memory modules. Refer to the information below regarding RIMM memory
for types 6838 and 6848.
Computer Name
NetVista Types 6838, 6848
Note: Both memory channels must be populated the same.
v RIMM sockets 1 and 3 are on memory channel A.
v RIMM sockets 2 and 4 are on memory channel B.
Each RIMM socket supports a maximum of 512 MB of memory.
install the new RIMM. (You must also do the same with the other memory
Channel).
install a C-RIMM. (You must also do the same with the other memory Channel).
Pair 2
3 4
C-RIMM C-RIMM
RIMM RIMM
RIMM Memory Module
Size Memory
64 MB 128 MB 256 PC600 PC800
MB 512 MB
Type
RDRAM
ECC/Non-ECC