CISCO Router Memory

All numbers for Table 1, 2 and 3 are for internal DRAM/Flash only. For Flash Cards/Disks, see Table 4.

Column "E?" is a field that indicates if the unit supports external flash memory (See Table 4).

Memory given as 'standard' (Std) will always be sold as an optimal configuration - for example, the 3660 comes with 32Mb DRAM default, and this is given as a single 32Mb module, instead of 2 x 16Mb. This is always the case unless there is a severe memory component shortage.

Table 1 - SOHO/SMB Routers




Notes - SOHO/SMB Router Memory

806/826's used to come with less DRAM (16Mb) standard.
Routers shipped after April 2002 come with 32Mb as default (and maximum).

Newer 8xx/SOHO's come with internal flash where 2Mb is devoted to the web installer.
This is unusable for system images, and is not counted in the table for that very reason.

2500's used to ship with 2Mb DRAM fixed to the motherboard, so some older models may report 2Mb more than normal.
AS2500's also ship with either 4 or 8Mb DRAM standard, depending on IOS ordered.

1721/51/60 shipped prior to August 18 2003 had 16MB flash and 32-64 MB DRAM.

83x's shipped prior to May 2003 shipped with 8MB flash standard.


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Table 2 - Midrange/Access Routers



Notes - Midrange/Access Routers

2610-21's were first shipped with 16Mb DRAM, then 24Mb, then standardized on 32Mb before EOS.

262x's assembled prior to March, 2001 used a bootROM incompatible with the 32Mb Flash module from the
265x series and must be upgraded to the new bootrom to be able to use this module.

36xx routers shipped prior to mid-May of 2002 shipped with 8Mb default flash memory.

On any 4x00M, all 2-slot memory must have either a single chip installed or have same-size chips installed.

26xxXM's shipped prior to August 18, 2003 came, in most cases, with 32MB DRAM and 16 MB Flash.

26xxXM's shipped prior to April 2004 had a maximum DRAM capacity of 128MB. This was increased in that
month to 256MB through an upgraded bootROM which can be ordered separately for older 2600XM's. The IOS
required to utilize and report any memory over 128MB will be released in Fall 2004 in the 12.3T train.

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Table 3 - Core Routers



Notes - Core Routers

Some models of I/O, I/O-FE, and I/O-FE-MII had 4Mb Bootflash socketed, others have it fixed onboard.

NPE-100/150/200 and VIP2-10/15/20/40 must pair memory SIMM's.

12000 series line cards always use paired packet memory, in dedicated "TX" and "RX" banks…
for example, 2x64MB for receive and 2x64MB for transmit (in 256MB configuration).

PRE and PRE-1 differ in PXF memory - 512MB (former) or 1GB (latter). PRE-1 is required for broadband.

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Table 4 External Flash



Notes - External Flash

Fields in light orange denote what ships, by default, with the product (if any is default at all).

Technically speaking, most sizes of cards will work in most routers, so long as they are "less than" the
maximum size it can officially support. What is listed here are what the CCO Docs list and/or what is orderable.
Therefore, a smaller or larger card "may" work, but likely will not be supported by TAC.

To see if a card can be interchanged between different model routers, please refer to the following URL:
http://www.cisco.com/warp/public/63/pcmciamatrix.html

The 12000 series PRP-2 also includes the options of adding one or both of the following directly to the
mainboard, internally: 1) a 1GB CompactFlash disk, 2) a 40GB hard disk.

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Identifying Router DRAM

In most routers, the memory chip configuration is easily discernable, due to the router either only having fixed memory, or the router having only one DRAM slot. In some cases, however, there are multiple slots. In those cases, there are sometimes ways to figure out the memory layout (i.e. is my 3640's 64MB DRAM in 2x32MB or 4x16MB) through software, without having to physically open the chassis. Such procedures are listed below. Note that these procedures do not cover all multi-memory-slot routers... for some router models, software methods are impossible. This is not to say that, in the future, IOS will not include other models – just that, currently, there is no way to do so.



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