Cisco 3631 Instalační příručka stáhnout pdf (Strana 3)

Upgrading System Memory in Cisco 3600 Series Routers

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Memory Configurations

For information on configuring dynamic (DRAM and SDRAM) and Cisco Flash memory, see the

following sections.

Dynamic Memory

You can configure DRAM or SDRAM as a mixture of primary or main memory that is reserved for the

CPU and shared memory that is used for data transmitted or received by modules and WAN interface

cards.

To examine current dynamic memory status or reconfigure memory allocation, do the following as

appropriate:

Step 1 To see how much memory is currently installed in your router, enter the show version command in

EXEC mode. Near the middle of the resulting output, locate a message similar to the following:

Cisco XXXX processor (revision X) with 24576K/8192K bytes of memory.

This line shows how much memory is installed (in this example, 24576K/8192K). The first number

represents primary memory; the second number represents shared memory.

Step 2 To configure the proportion of DRAM or SDRAM devoted to main memory and to shared memory,

enter the memory-size iomem command in global configuration mode.

Note For information about these and related commands, refer to the Cisco IOS configuration guides and

command references. See the “Obtaining Documentation” section on page 38 for information about

these publications.

DRAM SIMMs (Cisco 3620 and Cisco 3640 Routers)

Cisco 3620 and Cisco 3640 routers each contain four SIMM sockets for DRAM: bank 0 (SIMM 0),

bank 1 (SIMM 1), bank 2 (SIMM 2), and bank 3 (SIMM 3). A socket corresponds to one bank of

memory. Each socket can hold one DRAM SIMM of any size permitted for that router.

Banks must be filled consecutively with no gaps. Start filling from bank 0, and start emptying from

bank 3. Bank 0 must always be filled first and emptied last.

DRAM supports 32-bit and 64-bit operation as follows:

• Cisco 3620: Supports 32-bit operation only.

• Cisco 3640: Supports either 32- or 64-bit operation. Router performance is approximately 20

percent slower in 32-bit mode than in 64-bit mode. To use 64-bit mode, you must install DRAM

SIMMs in pairs of the same size. Generally, basic software feature sets (such as IP) use 32-bit

DRAM SIMMs and robust software feature sets (such as Enterprise) use 64-bit DRAM SIMMs.

Follow these rules to use 64-bit operation:

• SIMMs in banks 0 and 1 must:

–

Be the same size (in megabytes)

1 2 3 4 5 6 7 8 ... 43 44

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