The EEPROM it's a low cost solution but it limits your number of writes in. The NVRAM is more expensive and it depends on the baterry life. Best it's to use FRAM from RAMTRON.
NVRAM more expensive than EEPROM but NVRAM have better performance(speed). Write cycle of EEPROM less than NVRAM. So if you use many read/write process better use NVRAM rather than EEPROM
Usually it's in the datasheet, and it goes from 100.000 to about 1 milion erase writes cycles. The specifications are for the worst condition of temperature and voltage. There are some algorithms to increase your EEPROM life time but are code size consuming (you can use a counter for the number of times that you wrote in a cell, and to shift to another EEPROM cell when you are reach the write limit)
geppoilfolle said:
What are the characteristics of FRAMs? I never heard about them until now.