Data write rate

Hello! I'm new here, and i'm doing my first steps with Arduino. But before i acquire it i need to know the data write rate on the diferent memories (flash, sram, eeprom, sd in case it has a sd slot) of típical arduino boards and shields. I can't find it anywhere.

Thank you all!

Your program can't write to flash. Only the bootloader code can. It takes 3.3mS to write a byte to EEPROM. SRAM is 1 or 2 clock cycles - storing a variable value is writing to SRAM for example. SD - depends on what you are doing. The SDfat library is very good.