Cisco Memory and Flash

Cisco memory and flash covers two quite different things, and it is worth being clear which one you need.

UCS server memory

Registered and load-reduced DIMMs for Cisco UCS servers, in DDR3 and DDR4. Typical parts are PC3-10600 in DDR3 and PC4-17000, PC4-19200, PC4-21300 and PC4-25600 in DDR4, in single, dual, quad and octa-rank configurations. This is standard server memory in the technical sense, but it carries Cisco part numbers such as the UCS-MR and UCS-ML prefixes.

Router and switch flash

Storage for IOS images and configuration on Cisco network platforms:

• CompactFlash cards for router platforms, in capacities from tens of megabytes upward
• PCMCIA flash cards for the older chassis
• Onboard flash modules for specific switch and router series

Capacities here look small by modern standards because they are sized to hold an IOS image, not user data. That is exactly why they matter: if the flash is too small for the image the platform needs, the upgrade simply cannot proceed.

Why Cisco-coded parts matter here

Cisco platforms are conservative about what they accept. Memory and flash are validated against the platform, and a physically identical part without the right identification may not be recognised. This is more pronounced on network platforms than on UCS servers, where the memory is closer to industry standard.

Rank and capacity rules also apply on UCS as on any server: the supported combinations depend on the processor and the population order, and mixing ranks arbitrarily across channels is not safe.

Send us the platform and the IOS or firmware version you are targeting and we will confirm the part and the capacity it actually needs.