Funtionality of RAM & Flash memmory in network switch

[Aiz 10]

How does the amount of RAM & Flash memory affects a switch performance ?. is it really like performance improves with increase in the amount of these memories. what exact role they play in switch performance. As there are other factors as well like :- throughput; switch fabric; switching capacity etc..? Anyone pls help in understanding these factors.. I want to buy advance L3, bit confused between HP 5500 & cisco 3850..

 

[kanewolf]

Flash is used to save the switch OS. RAM is used to run the OS and to buffer data (if required). Both of the switches you listed are fixed port configuration devices. If you have a switch that has to keep 1000s of MAC and IP addresses or you are going to have a lot of ACLs then more RAM is beneficial.
Any new top-tier switch will run at the advertised line rate. Switching capacity is usually just number of ports times max port speed.