2014-04-30, 07:48
SDRAM will be faster than SD card, but Linux will also cache the SD card file accesses so in my opinion you'll get similar performance with "noram" thanks to OS file caching, but without dedicating a fixed chunk of memory to load the entirety of SYSTEM into RAM
Linux will use whatever RAM is available for file caching, and give that memory back when a program needs it, whereas dedicating 110MB+ of RAM to a ram disk is memory that can't be used for any other purpose.
Bear in mind also that a significant proportion of SYSTEM is made up of code that most users won't ever be using, for instance the WiFi modules and drivers will all be sat in your RAM disk even if you don't have any wifi hardware.
Linux will use whatever RAM is available for file caching, and give that memory back when a program needs it, whereas dedicating 110MB+ of RAM to a ram disk is memory that can't be used for any other purpose.
Bear in mind also that a significant proportion of SYSTEM is made up of code that most users won't ever be using, for instance the WiFi modules and drivers will all be sat in your RAM disk even if you don't have any wifi hardware.