Cisco 2691 - Cisco 2600 Series Hardware Installation Manual

Upgrading DRAM

Cisco 2691

This section describes how to upgrade synchronous dynamic random access memory (SDRAM) dual
in-line memory modules (DIMMs) in the Cisco 2691 routers.
The Cisco 2691 router contains two 168-pin DIMM sockets for SDRAM. Each socket can be filled with
a single 64-bit-wide, 168-pin SDRAM DIMM. You can configure SDRAM as a mixture of main
memory, which is reserved for the CPU, and shared memory, which is used for data transmitted or
received by modules and WAN interface cards. See
To see how much memory is currently installed in the router, enter the show version command while
the router is in privileged EXEC mode (
similar to the following displays:
cisco 2691 (R7000) processor (revision 0.5) with 121856K/9216K bytes of memory.
This line shows how much memory is installed (in this example, 24576K/8192K). The first number
represents primary memory and the second number represents shared memory. Your router supports up
to 256 MB of SDRAM.
Each DIMM slot corresponds to one bank of memory. Fill banks from 0, and empty banks starting with
1. Bank 0 must always be filled first and emptied last.
The Cisco 2691 router supports both parity and nonparity PC-100 DIMMs ranging in capacity from
64 to 128 MB. Only certain combinations of SDRAM DIMMs are permitted. (See
An advantage of parity DIMMs over nonparity DIMMs is how much easier memory errors are
Note
identified; a disadvantage however is lower processing speed.
To use a 64-bit mode SDRAM configuration, the DIMM in slot 1 must be less than or equal to the
Note
size of the DIMM in slot 0.
Cisco 2600 Series Routers Hardware Installation Guide
B-10
Figure B-7 for DIMM locations.
). Near the middle of the resulting output, a message
Router#
Appendix B Maintaining the Router
Table B-4.)
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