If change the memory physical on a router, that affect in the config?

[Becky Navas]

Hello, 

We need to change the physical memory  on a ISR4331 router for a 8GB physical memory , actually it has a 4GB physical memory and 2GB for DRAM. If we change the memory, this can affect the configuration actual on my router? 

[Joseph W. Doherty]

". . . 4GB physical memory and 2GB for DRAM."

Generally physical memory is DRAM.  Are you referring to flash RAM vs. DRAM, or how DRAM is allocated between "router" working memory and I/O memory (if the 4K allows configurating their ratios [I don't recall if the 4Ks do])?  Or?

I.e. could you clarify your question?

Aside from the clarification, if your router has 4GB DRAM and you want to increase it, you probably don't need to change the configuration but your router's hardware installation documentation, should note such impact.

e.g.

https://www.cisco.com/c/en/us/td/docs/routers/access/4400/hardware/installation/guide4400-4300/C4400_isr/FRUs_Modules.html#35440

https://www.cisco.com/c/en/us/td/docs/routers/access/4400/flashmemory/isr4000_flashmem.html#pgfId-1080760